Scholarly Literature
This is an aggregation of scholarly literature from peer-reviewed journals, bioRxiv , medRxiv and arXiv preprint servers focused on natural and engineered selfish genetic elements and genetic biocontrol. New citations are added as they appear. This content is intended for anyone interested in the scholarly literature on gene drive and genetic biocontrol.
Improvement of colony management in insect mass-rearing for sterile insect technique applications
35183Adly M.M. Abd-Alla, Anne Geiger, David Haymer, Insect Science, 2025-09-29 08:40:15.
Sterile Insect Technique (SIT) applications against major insect pests and disease vectors rely on the cost-effective production of high-quality sterile males. This largely depends on the optimal management of target pest colonies by maximizing the benefits provided by a genetically rich and pathogen-free mother colony, the presence of symbiotic microorganisms, and efficient domestication, mass-rearing, irradiation, and release processes. At the same time microbial (bacteria, fungi, microsporidia, and viruses) pathogen outbreaks should be minimized or eliminated, and the use of hazardous chemicals restricted. The optimization of the colony management strategies for different SIT target insects will ensure a standardized high-quality mass-rearing process and the cost-effective production of sterile males with enhanced field performance and male mating competitiveness. The aims of the Coordinated Research Project (CRP) were to develop best practices for insect colony management for the cost-effective production of high-quality sterile males for SIT applications against major insect pests and disease vectors through a multidisciplinary approach involving entomologists, geneticists, ecologists, microbiologists, pathologists, virologists, and mass-rearing experts.
Leveraging Sex Determination Systems for Genetic Biocontrol of Dipteran Pests
35178Maxwell J. Scott, Zhijian Tu, Current Opinion in Insect Science, 2025-09-26 14:24:25.
Genetic biocontrol is an increasingly important way to suppress insect pest populations and to mitigate their economic and health impact. One key advantage is that it is species-specific as it relies on mating of released males with wild females to either suppress or modify populations. The latter is through rendering females incompetent at disease transmission. Sex separation is critical to ensure the efficiency of these control programs, and it is essential in the case of vector control to avoid releasing females that can transmit pathogens. Modern genetic methods provide the opportunity to target or manipulate components of the sex determination systems to facilitate genetic biocontrol with new means to effectively accomplish sex-specific selection, lethality, or sterility. For example, sex-specific splicing elements in genes in the sex determination pathway are used to produce sex-specific markers. Sex-linked recessive lethal alleles are used to differentially eliminate the transgene-marked sex chromosome from males to produce non-transgenic males. Knocking out or knocking down sex-specific isoforms of genes in the sex determination pathway is employed to confer female-specific lethality or sterility. Sex determination pathways and sex chromosomes are also targeted for gene drives that suppress pest populations by introducing extreme sex ratio biases. Here we review these and other recent advances on the genetic technologies for pest control that have benefited from knowledge of sex determination systems in Diptera.
The role of the transformer gene in sex determination and its employment in CRISPR/Cas9-based homing gene drive in the global fruit pest Drosophila suzukii
35172Dan Deng, Xueying Yi, Wen Wen, Liuqing He, Wei Peng, Insect Biochemistry and Molecular Biology, 184. 2025-09-26 14:04:36.
Sex determination of Diptera is established by the cascade genes such as transformer (tra), though the primary signals for sex determination differ among different insects. Here, we report the isolation, expression and function of tra gene in an invasive pest, Drosophila suzukii, and study the potential use of the D. suzukii tra (Dstra) gene in CRISPR/Cas9-based homing gene drive for genetic-based pest management. The Dstra gene is highly conserved in structure and has a sex-specific transcript. To test the function of this gene in sex determination, Dstra dsRNA was injected into embryos. Almost all XX embryos developed into masculinized phenotypic male adults with intersex morphology. Abnormal ovaries were revealed in XX pseudomales upon dissection. Based on the necessary role of Dstra for female development, we developed and evaluated a homing gene drive that targets Dstra in D. suzukii. The drive component consisting of multiplex Dstra single guide RNAs and Cas9 with Dsvasa promoter was introduced into the Dstra locus. Abnormal development of both the external genitalia and gonads was observed in G0 and G1 chromosomal female adults that expressed the male-specific doublesex (dsx) transcript. Interestingly, knocking out Dstra led to significantly reduced fertility in adults of corresponding sex and moderate transmission rates of the DsRed gene (63.54 %) were observed. Our results not only confirm the conserved function of the Dstra gene in sex determination, but also highlight the potential of sex conversion-based suppression gene-drive strategy targeting the Dstra gene in controlling of D. suzukii populations.
Effect of egg irradiation on development and sterility of wild-type and Wolbachia trans-infected Aedes aegypti mosquito vectors
35170Kittayapong P, Ninphanomchai S, Thayanukul P, Limohpasmanee W, PLoS One, 20. 2025-09-26 13:56:46.
Sterile Insect Technique (SIT), Incompatible Insect Technique (IIT) or a combination of the two has become alternative promising vector control approaches. In order to apply these approaches, the targeted mosquitoes need to be sterilized and released. So far, the irradiation of mosquitoes has been conducted at the pupae or adult stages. In this study, we investigated the possibility of applying X-ray irradiation at the egg stage and also assessed the effect on the development and sterility of both wild-type and Wolbachia trans-infected Aedes aegypti mosquito vectors. The eggs of both wild-type and Wolbachia trans-infected lines were irradiated using X-ray at the doses of 1, 3, 5 and 7 Gy. Development of immature stages was observed. For wild-type Ae. aegypti, X-ray irradiation at the doses from 3 Gy decreased the development of the first-instar larvae and increased the development of the third-instar larvae but there was no effect on pupae. For Wolbachia trans-infected ones, a irradiation dose as low as 1 Gy could increase the development of the forth-instar larvae while an irradiation dose of 7 Gy induced significantly high mortality to the pupae (p < 0.05). To assess sterility, males and females that emerged from irradiated eggs were mated with the non-irradiated ones. Our results showed that an irradiation dose of 7 Gy significantly caused more than 90% sterility in both wild-type males and females (p < 0.05). However, this irradiation dose could be reduced to 5 Gy to sterilize both males and females infected with Wolbachia. Our findings revealed, for the first time, that applying a low-dose X-ray irradiation at the egg stage could sterilize both wild-type and Wolbachia trans-infected Ae. aegypti when they become adults. Egg irradiation could make the implementation of SIT, IIT or combined SIT/IIT for vector control much more feasible as the sterile eggs are easier to distribute and operate when compared to other developmental stages of mosquitoes.
SELECTING A LARVAL DIET FOR SCALABLE MASS-REARING OF AEDES AEGYPTI IN STERILE INSECT TECHNIQUE APPLICATIONS
35168Aryaprema VS, Blore K, Sypes O, et al., Journal of the American Mosquito Control Association, 2025-09-26 13:51:54.
Controlling Aedes aegypti populations through traditional methods is increasingly difficult due to the development of insecticide resistance and their use of cryptic breeding habitats. The sterile insect technique has emerged as an effective tool for integrated vector management. Still, its success depends on the ability to mass-rear large numbers of high-quality mosquitoes. Choosing an appropriate larval diet is crucial for scalable mass-rearing, as it directly influences mosquito development, survival, and overall production efficiency. This study compared the effects of 3 larval diets: 1) TetraMin® Tropical Flakes, 2) Ziegler® Tropical Pro-Start45 Meal, and 3) bovine liver powder delivered in cellulose capsules, on the growth and performance of male Ae. aegypti under simulated mass-rearing conditions. Ziegler-reared mosquitoes had significantly larger pupal and adult sizes than those reared on Tetramin or liver powder. The Tetramin diet produced smaller adults, but with longevity comparable to that of the Ziegler diet, whereas the liver powder diet resulted in mosquitoes of similar size to those of the Tetramin diet, but with reduced longevity. While all 3 diets demonstrated viability for mass-rearing, their suitability depends on program-specific goals and constraints. The liver powder diet offered a good balance of biological performance and operational efficiency, but at a substantially higher economic cost. With further optimization of feeding regimens, the Ziegler diet shows the most significant potential to deliver high biological quality at the lowest price, making it a strong candidate for scalable mass-rearing programs.
Heterogeneity in inhibition of genetically diverse dengue virus strains by Wolbachia
35165Afeez Sodeinde, Emilie Finch, Ke Li, et al., bioRxiv, 2025-09-26 13:29:40.
The release of Aedes aegypti mosquitoes transinfected with the virus-inhibiting Wolbachia bacterium has the potential to reduce the burden caused by dengue virus (DENV). However, the robustness of this control strategy across the wide genetic diversity of DENV remains unknown. Here, we systematically tested two commonly used Wolbachia strains (wAlbB and wMelM) for their ability to inhibit 60 genetically diverse DENV isolates spanning all four serotypes. We found stronger inhibition by wMelM (median relative dissemination: 0.04) than wAlbB (median relative dissemination: 0.19). Furthermore, while we found substantial heterogeneity in inhibition across DENV isolates, we found that more DENV-3 isolates were weakly inhibited (median relative dissemination: 0.47 for wAlbB and 0.39 for wMelM) compared to the other serotypes (median relative disseminations: 0.10-0.18 for wAlbB and 0-0.11 for wMelM). Using transmission dynamic models, we further showed that differential Wolbachia inhibition results in increased probability of reemergence, particularly in high transmission intensity settings, with strong selection for DENV strains that have higher relative dissemination in mosquitoes. Our work highlights the importance of considering DENV genetic diversity, including the long-term risk of selection, in Wolbachia-based control interventions.
Apprehension of Technosciences and Initiation to Education for Uncertainty: Case of Gene Drive
35163Hayet Saoudi and Hanen Bouamoud, Qualitative Approaches to Pedagogical Engineering, 2025-09-22 15:39:06.
This research falls within the framework of education about uncertainty. The authors focused on one of the technosciences, namely genetic engineering, and treated it as a ‘socially acute issue'. The research involved a group of Tunisian third-year students in life and earth sciences. They are a group of potential future teachers. They set up a three-phase experiment. The first phase consisted of a pre-test quiz, aimed at assessing the students' scientific knowledge and the forms of uncertainty they mobilised. The second phase consisted of watching videos on technoscience and genes. The third phase consisted of a post-test quiz designed to monitor changes in the quality of the scientific knowledge required and to highlight the forms of uncertainty used. For the analysis, the authors used analytical grids to characterise the quality of the scientific knowledge and the forms of uncertainty involved. The results show that integrating socially current issues has a significant effect on education about uncertainty and on the acquisition of scientific knowledge.
Rapid protamine evolution suppresses meiotic drive in Drosophila
35159Ching-Ho Chang, Aida Flor de la Cruz, Isabel Mejia Natividad, Alex Noyola, Harmit S. Malik, bioRxiv, 2025-09-22 10:55:08.
Many animal species replace histones with protamines during spermatogenesis. Despite their importance for sperm function, protamines rapidly evolve in many species; the biological causes behind their rapid evolution remain unknown. Here, using in vivo gene replacement, we investigated the causes and consequences underlying the rapid evolution of protamine Mst77F, which is essential for male fertility in D. melanogaster. Mst77F ortholog replacements led to defects in DNA compaction of X-chromosome-bearing sperm compared to Y-chromosome-bearing sperm during spermatogenesis, resulting in fewer X-bearing mature sperm and male-biased progeny. Unlike D. melanogaster, Mst77F is not essential for male fertility in D. yakuba but is still required to suppress sex-ratio distortion. Our results suggest that relentless pressure to suppress sex chromosomal meiotic drive drives the rapid evolution of protamines.
Suppression of Aedes albopictus in Sri Lanka using the Sterile Insect Technique (SIT) with a sustained effect
35157Menaka Hapugoda, Nilmini Silva Gunawardene, Tharaka Ranathunge, Sudath Samaraweera, K. Karunathilake, Bazoumana B.D. Sow, Gayan Parakrama Withanage, Indika Weerasinghe, Hamidou Maiga and Jeremy Bouyer, Parasite, 32. 2025-09-22 10:50:08.
Dengue fever remains a significant public health concern in Sri Lanka, leading to recurrent epidemics and imposing substantial socio-economic burdens. This study aimed to assess the efficacy of the Sterile Insect Technique (SIT) against Aedes albopictus (Skuse), the predominant dengue vector in the country, through a pilot field trial of an Integrated Vector Management (IVM) strategy including the SIT. The pilot trial was conducted in the Gampaha district, which reports the second-highest number of dengue cases in the country. A total of 3,300,000 sterile males, exposed to a 50 Gy radiation dose, were released over 33 weeks (100,000/week) within a 30-hectare release area. Entomological assessments were conducted at 115 trapping stations over a period of 71 weeks (October 2020–August 2022). Induced sterility of 98.16% in mosquito eggs was reached within the release area as compared to the control area (binomial generalized linear mixed model, deviance 2.408, df = 2, p = 0.016), indicating a notable impact of the SIT. The trial achieved nearly 98% suppression of adult vector mosquitoes, with a sustained suppression effect for 13 weeks post cessation of releases. These findings suggest that SIT can be effectively integrated as a potential additional tool into the future IVM strategy in Sri Lanka.
Single-cell consequences of X-linked meiotic drive in stalk-eyed flies
35155Price PD, Parkus SM, Lloyd VJ, Alston BT, Bradshaw SL, Bates S, et al., PLoS Genet, 21. 2025-09-22 10:33:47.
Meiotic drivers, a class of selfish gene, are frequently located on sex chromosomes and have dramatic impacts on gamete development. However, our understanding of their molecular consequences for gamete production and sex chromosome regulation has focused on a handful of model organisms. In this study, we use single-cell RNA-sequencing approaches to produce a single-cell atlas of the testis of the stalk-eyed fly, Teleopsis dalmanni. This species harbours an X-linked meiotic driver where drive males produce more than 90% female offspring. First, we generate a comprehensive profile of the cellular and transcriptional landscape of spermatogenesis. We show limited evidence for meiotic sex chromosome inactivation and unique patterns of dosage compensation across spermatogenesis, relative to both other dipterans and insects in general. Finally, by comparing single-cell expression data between standard and drive males, we show that although there are significant differences in genome regulation, broad expression dynamics in the testis are conserved in the presence of meiotic drive. Notably, we highlight key genes with perturbed expression as a potential consequence of the disruption of spermatogenesis by the X-linked meiotic driver.
Advances in population-based interventions to control falciparum malaria
35153Samuel E Glossop, Thomas J Peto, Bipin Adhikari, Transactions of The Royal Society of Tropical Medicine and Hygiene, 2025-09-22 10:26:25.
Malaria is a complex disease and transmission can be prevented in multiple ways. A range of interventions to achieve this became widely available from the year 2000, and cases continually declined, but progress has plateaued since 2015. This review aims to cover the population-level prevention strategies responsible for this and those that could continue this progress, focusing on how they can be successfully integrated. Insecticide-treated nets (ITNs) made the most substantial contribution to reducing malaria mortality, but their distribution, access and use remains suboptimal while development of insecticide resistance requires continuous adaptation. Chemoprevention provides protections to tens of millions of people, primarily children in sub-Saharan Africa, but is also threatened by the emergence and spread of drug resistance. These strategies may have reached a point of saturation for reducing morbidity and mortality, thus calling for innovative developments to build upon more basic approaches such as accurate early diagnosis, appropriate treatment and improved housing. The R21/Matrix-M vaccine is a significant improvement over the RTS,S/AS01 vaccine, with greater efficacy, lower cost and scalable mass production. Field trials of current monoclonal antibodies (mAbs) suggest that next-generation mAbs could be a promising tool for seasonal chemoprophylaxis. Furthermore, gene drives may have the potential to eradicate entire populations of malaria-transmitting mosquitoes. A multifaceted approach combining these new strategies with traditional approaches (ITNs and chemoprevention) offers a framework to reinvigorate progress towards malaria elimination.
Reprogramming Sex for Vector Control: Maleness-Associated Transgenes in Aedes albopictus
35151Doron Shalom Yishai Zaada, Philippos Aris Papathanos, Eric Marois, Current Opinion in Insect Science, 2025-09-22 10:21:15.
Among other challenges, the world currently faces the expansion of pest insects such as the tiger mosquito Aedes albopictus, a growing threat to public health due to the pathogens it can transmit. Current control approaches based on insecticides or elimination of mosquito larval breeding sites are insufficient to suppress this highly invasive species. The discovery of Nix, a gene necessary and sufficient to determine the male sex in this mosquito, opens new prospects for genetic control strategies, in particular those based on transgenes that convert females into males, or that reduce female fitness. Such forms of genetic control could be effective on larger spatial and time scales compared to classical control approaches. This overview of current and emerging genetic control strategies targeting Aedes mosquitoes emphasizes the unique characteristics of Ae. albopictus, that make it particularly amenable to masculinization-based genetic control.
Experimental demonstration of daisy chain gene drive and modelling of daisy suppression systems
35147Jialiang Guo, Weizhe Chen, Jackson Champer, bioRxiv, 2025-09-22 10:06:58.
CRISPR-based gene drive can address ecological problems by biased inheritance coupled with an effector for either population modification of suppression. However, the potential risk of uncontrolled spread impedes some applications of gene drive. Daisy chain gene drives have received much attention as a potential approach to overcome this problem. They potentially allow the efficient spread of drive elements in a target population, but are ultimately self-limiting. This is achieved by splitting a normal gene drive system into multiple dependent drive elements, where each element can bias the inheritance of another, except one non-driving element. With the successive loss of each chain link, the spread of transgenic elements will slow down and eventually stop. Here, we use modelling to assess the population dynamics of daisy chain drives in both panmictic and continuous space models, focusing on suppression systems. We find that achieving population elimination through a single release of daisy chain gene drives is possible but difficult, with relatively high requirements for drive performance and release size. These effects are substantially amplified in spatial models. We also constructed two configurations of daisy chain gene drives in Drosophila melanogaster as a proof-of-principle. One is a rescue drive for population modification, and the other aims for population suppression by targeting a haplosufficient female fertility gene. These drives all functioned within expectations at moderate efficiency in individual crosses. However, the drive design failed to spread in cage populations because of higher than expected fitness costs. Overall, our study demonstrates that daisy chain systems may be promising candidates for both modification and suppression, but challenges remain in both construction and potential deployment in large regions.
Natural Selection of Synthetic Gene Drives for Population Suppression Can Favor an Intermediate Strength of Drive
35141P. J. Beaghton and Austin Burt, The American Naturalist, 206. 2025-09-16 15:55:03.
Synthetic gene drives are being investigated as tools to suppress pest populations, and it is important to understand how natural selection will act on variant drivers that may either arise by de novo mutation or be intentionally released. In this study, we extend previous spatially implicit stochastic models to examine the evolutionary dynamics of synthetic driving Y chromosomes in patchy environments when population size is responding dynamically to the spread of the driver and derive conditions for the existence of an evolutionarily stable strategy (ESS) for drive strength. Under broad conditions, an intermediate drive strength emerges as the ESS, capable of outcompeting both stronger and weaker variants. Additionally, we show how the intentional release of two drivers straddling the ESS can help stabilize population dynamics. Finally, inbreeding depression has the effect of expanding the range of conditions under which no intermediate ESS exists, with ever stronger drive being selected until the population is eliminated. These results provide insights into the expected evolutionary trajectories of gene drive systems, with important implications for the design and release of gene drives for pest and vector control.
The Urgent Need for More Research on Wolbachia-Based Mosquito Interventions in Public Health
35133Osvaldo Marinotti, Acta Tropica, 2025-09-15 15:36:56.
The release of Wolbachia pipientis-infected Aedes aegypti mosquitoes has emerged as a novel strategy to reduce the transmission of arboviruses such as dengue, chikungunya, and Zika. Wolbachia-based approaches to dengue control include population replacement, which reduces vector competence by establishing Wolbachia in wild populations of Aedes aegypti, and population suppression, which lowers mosquito densities through cytoplasmic incompatibility. Field trials of the population replacement strategy, based on wMel Wolbachia-infected mosquitoes, have shown variable success and concerns persist about long-term efficacy, safety and ecological impact. Uncertainties arise from an incomplete understanding of the mechanisms underlying pathogen blocking, possible bacteria and vector strain-specific effects, and the influence of environmental, host, and viral factors on the success of such a strategy. Moreover, some Wolbachia strains may enhance mosquito susceptibility to certain pathogens. Additionally, large-scale deployment raises the possibility of biodiversity disruption and the emergence of viral resistance. Given these unresolved concerns, it is premature and potentially irresponsible to expand the program to new areas without first rigorously assessing its safety, efficacy and sustainability.
Engagement for genetic modification technologies in conservation: For whom, how, and for what ends?
35126Sylvia Nissen, Franca A. Buelow, Riley Taitingfong, Amanda Black, Environmental Science & Policy, 171. 2025-09-09 09:15:42.
Questions of engagement loom large for the use of genetic modification technologies in conservation. As scientific teams rapidly move towards implementing changes that will fundamentally alter entire species, concerns are regularly raised that associated engagement activities are inadequate. It is therefore vital to take stock of recent social research that critically examines how engagement is being enacted: who is engaged and by whom, how and on what terms, and for whom or what those processes serve. Despite a rise in calls for engagement, our review shows emergent gestures towards engagement by developers and regulators lean strongly towards narrow instrumental approaches that reinforce knowledge hierarchies and existing power imbalances. It contributes to engagement practices that are often vague and tokenistic, and focused on one-way education and snapshots of opinion, rather than mutual reciprocity and dialogue. To counter these undercurrents, our review draws attention to the ways social researchers are seeking to reorient engagement for genetic modification towards its more substantive and democratic possibilities, through articulating process, amplifying plurality, and acknowledging contestation.
Wolbachia Infection in Iranian Malaria Vectors: Prevalence and Biocontrol Implications
35124Shahin Saeedi, Fateh Karimian, Seyed Hassan Moosa-Kazemi, et al., Tropical Medicine & International health, 2025-09-08 08:50:24.
Wolbachia-based vector control is an emerging tool in malaria prevention research. This study evaluates Wolbachia infection in Iranian mosquitoes, focusing on seven known malaria vectors. Mosquitoes were collected from nine provinces of Iran (2016–2019), and Wolbachia infection status was analysed via PCR targeting eight genes: wsp, gatB, ftsZ, dnaA, groEL, gltA, CoxA and fbpA. We examined 1094 specimens from seven malaria vectors (Anopheles stephensi Liston, 1901; Anopheles culicifacies s.l. James, 1901; Anopheles fluviatilis s.l. James, 1902; Anopheles maculipennis s.l. Meigen, 1818; Anopheles sacharovi Favr, 1903; Anopheles dthali Patton, 1905; Anopheles superpictus s.l. Grassi, 1899), four non-malaria vectors (Anopheles mongolensis Linton, Lee and Curtis, 2005; Anopheles hyrcanus Pallas, 1771; Anopheles claviger Meigen, 1804; Anopheles turkhudi Liston, 1901) and three Culex species (Culex pipiens Linnaeus, 1758; Culex perexiguus Theobald, 1903; Culex theileri Theobald, 1903). PCR revealed Wolbachia DNA exclusively in An. dthali and Culex species, with infection rates of 73.4% for An. dthali and 77.78%–96.77% for Culex, notably higher in males. Wolbachia was detected in all regions except one in the north. Phylogenetic analysis revealed Wolbachia strains in An. dthali and Culex belong to supergroup B, closely related to strains in An. moucheti and An. demeilloni. This suggests broader applications for biocontrol strategies. The high Wolbachia prevalence in An. dthali is promising for malaria prevention. Future research should confirm cytoplasmic incompatibility and explore wAdth's potential to block malaria transmission.
Sequence and expression analysis of potential spermatogenesis-specific gene cognates in the Caribbean fruit fly, Anastrepha suspensa
35118Alfred M. Handler, Richard B. Furlong, Chao Chen, Daniel A. Hahn, Insect Science, 2025-09-08 08:26:08.
The sterile insect technique (SIT) is a highly effective biologically-based method for the suppression of many insect pest populations. SIT efficacy could be improved by methods of male sterilization that avoid the use of irradiation that can result in diminished fitness and mating competitiveness. Alternative sterilization methods include conditional disruption of genes for male fertility, or using their sperm-specific promoters to drive the expression of genes for lethal effectors. Testing has begun for the testis-specific β2-tubulin gene, though additional male fertility genes are required for redundancy or replacement, and for species where the β2-tubulin isoform does not exist or is not testis-specific. Here we had the goal of identifying and characterizing the sequence and transcriptional expression of two genes in the caribfly, Anastrepha suspensa, that are cognates of D. melanogaster spermatocyte-specific male fertility genes. In Drosophila, wampa encodes a coiled-coil dynein subunit required for axonemal assembly essential to microtubule-based sperm motility, while Prosα6T is a proteasome subunit gene required for spermatid individualization and nuclear maturation. In A. suspensa a cognate to wampa exhibited testis-specific transcript expression, which was minimal in both male and female body tissue. A Prosα6T cognate was not apparent in A. suspensa, but its constitutive isoform, Prosα6, expresses in male testes, but also in male and female body tissue. Thus, for A. suspensa, wampa remains a strong candidate gene for male sterility strategies for SIT including a direct target for gene-editing knockout and use of its promoter for testis-specific toxicity or cell death in conditional expression systems.
Development and evaluation of pupal color-based genetic sexing strains in Anastrepha obliqua
35116Daisy P. Cárdenas-Enríquez, Víctor García-Martínez, Jorge Ibáñez-Palacios, et al., Insect Science, 2025-09-08 08:23:07.
Anastrepha obliqua, a neotropical pest widely distributed in the Americas, attacks mango and other tropical fruits. In Mexico, it is controlled through integrated pest management, using the Sterile Insect Technique (SIT) as a main component. The applicability of SIT is significantly improved with the use of genetic sexing strains (GSS) that allow the possibility to release exclusively sterile males, the primary component of the technique. This study reports the isolation and characterization of two pupal mutations: black pupae (bp) and sphere pupae (sp), allowing for the first time the development of a genetic sexing system based on pupal color in this species. Inheritance analyses from reciprocal crosses between wild-type and mutant individuals showed F2 phenotypic segregation consistent with a recessive Mendelian inheritance pattern, and linkage analysis indicated that the bp and sp loci are in separate chromosomes. Using the bp mutation, two GSS were developed through gamma irradiation [T(Y;bp+)/bp-22](GSS-22) and ethyl methanesulfonate treatment [T(Y;bp+)/bp-354](GSS-354). Both GSS exhibited sex-specific pupal differentiation but displayed a high frequency of recombinants. Despite an initial reduction in biological fitness, GSS-22 demonstrated greater genetic stability and a lower frequency of recombinants than GSS-354. Discrepancies between cytogenetic and genomic data, particularly regarding the localization of the gene responsible for the black pupae phenotype, underscore the need to integrate polytene chromosome and genomic analyses to characterize these translocations and improve GSS stability precisely. These results represent a breakthrough in the creation of genetic tools for the management of A. obliqua control.
Application of Sterile Insect Technique (SIT) for Aedes albopictus (Skuse, 1895) in Sri Lanka: Dose optimization, mating competitiveness and release ratios
35114Harishchandra J, Abeyewickreme W, Premaratne R, Hapugoda M, PLoS One, 20. 2025-09-05 08:04:10.
Sri Lanka has experienced severe dengue epidemics in recent years, despite the extensive vector control measures taken. Therefore, it is necessary to find sustainable vector control strategies against dengue. Novel vector control tools need to be tested for the feasibility of applying them against local vectors. Sterile Insect Technique (SIT) is an increasingly popular vector control technique which has been adopted by many countries to suppress insect pest populations and is being tested for dengue vectors. In this study, SIT was developed for Aedes albopictus (Skuse, 1895), one of the 2 dengue vectors present in Sri Lanka. The optimum radiation dose for sterilizing male pupae (age 24–48 hours) using a Co 60 source was determined based on the post-irradiation pupal and adult survival in males and induced sterility in females at different doses. Further, the effect of irradiation on mating competitiveness of the selected mosquito strain was assessed under laboratory and semi-field conditions. The optimum release ratio of irradiated males to wild males was assessed in laboratory and semi-field settings. The optimum radiation dose was 50 Gy among the series of doses (25, 30, 40, 50, 60, and 70 Gy) tested. When pupae were exposed to the optimal radiation dose, 100% pupal survival, 19-day median adult survival time and 99% induced sterility resulted. A 5:1 ratio of irradiated males to non-irradiated laboratory-reared or wild males in laboratory cages resulted in induced sterility of 75% and 62%, respectively. The respective values were 74% and 61% in large semi-field cages. Fried Competitiveness Index (FCI) of irradiated males against wild males of laboratory and wild origin were 0.63 and 0.43 in laboratory cages and 0.57 and 0.55 in large semi-field cages. The males of Ae. albopictus irradiated at 50 Gy are adequately sterile and are competitive against the wild males. The release ratio of 5:1 irradiated males to wild males is a suitable ratio for the field application of SIT. The findings of the study will be important for the development of a protocol for future application of SIT for Ae. albopictus in Sri Lanka.
Long-Term Durability and Public Health Impact of City-Wide wMel Wolbachia Mosquito Releases in Niterói, Brazil, During a Dengue Epidemic Surge
35107Anders, Katherine L., Gabriel Sylvestre Ribeiro, Renato da Silva Lopes, Pilar Amadeu, Thiago Rodrigues da Costa, Thais Irene Souza Riback, Karlos Diogo de Melo Chalegre, Wesley Pimentel de Oliveira, Cátia Cabral da Silva, Marcos Vinicius Ferreira Mendes B, Tropical Medicine and Infectious Disease, 10. 2025-09-02 18:57:03.
In 2024, the Americas experienced the largest dengue outbreak on record and Brazil was among the worst affected countries, reporting 6.6 million cases and 6200 deaths. We report the long-term entomological and epidemiological effectiveness of city-wide deployment of wMel-strain Wolbachia-infected Aedes aegypti in Niterói, a city of half a million people in Rio de Janeiro state, where Wolbachia releases across three-quarters of the urban population in 2017–2019 were expanded to remaining populated areas in 2023. wMel was durably established at ≥95% prevalence in Ae. aegypti populations throughout Niterói four years post-release, and up to seven years in the earliest release sites. Notified dengue case incidence in Niterói was 89% lower following Wolbachia releases, compared to the 10-year pre-intervention period of 2007–2016. Dengue incidence in Niterói in 2024, during a period of record high incidence in Brazil and the region, was 374 per 100,000 population, substantially lower than overall in Rio de Janeiro state (1884 per 100,000) and nationwide in Brazil (3157 per 100,000). Our findings show that city-wide Wolbachia coverage in Niterói provided sustained population-level reduction in dengue incidence throughout the five years post-intervention, including during the 2024 epidemic surge, averting an estimated three-quarters of the dengue case burden that may otherwise have been expected in Niterói in 2024.
Genomic Insights into Wolbachia Strain wCin2USA1 Reveal Promising Cytoplasmic Incompatibility Potential and Next-Generation Dengue Biocontrol
35098Istiaque Zaeem, Nurnabi Azad Jewel, Mohimenul Haque Rolin, et al., bioRxiv, 2025-09-01 19:59:21.
Dengue fever is one of the fastest-growing mosquito-borne diseases in the world, causing illness and economic challenges in many countries. Current mosquito control methods, such as insecticides, are often costly, less effective over time, and harmful to the environment. An alternative approach uses naturally occurring bacteria called Wolbachia, which live inside insects. When certain Wolbachia strains are introduced into mosquitoes, they can reduce the insects’ ability to spread viruses like dengue. In our study, we compared the genetic makeup of several Wolbachia strains to identify new candidates that may work better for controlling dengue. We discovered that a strain called wCin2USA1 has strong potential because it shares important features with two strains already used successfully, while also having unique advantages. These include genes that help prevent mosquitoes from reproducing normally when carrying different Wolbachia strains, which can reduce mosquito populations. Our findings suggest that wCin2USA1 could be developed as a new, environmentally friendly tool to help reduce dengue transmission.
Autosomally-encoded segregation distortion of sex chromosomes
35096Greenberg Naomi L., Patten Manus M. and Schenkel Martijn A., Proc. R. Soc. B., 292. 2025-09-01 19:48:42.
Some selfish genetic elements drive at meiosis to achieve transmission distortion, breaking the rules of Mendelian segregation to enhance their own evolutionary success. It has been shown that enhancers of drive must act in cis in order to gain the selfish benefit of drive and that suppressors of drive will be selected at unlinked loci. Here, we model the evolution of an autosomal trans-acting gene (Distorter) that causes the Y chromosome (or even 0 chromosome) to drive without driving itself, a phenomenon we call ‘remote-control meiotic drive’. We show that such a gene may spread in the population when linked to a second locus, Assister, whose alleles are transmitted at different frequencies through sperm as compared to eggs, for which we consider various scenarios, such as sexually antagonistic selection or sex-limited drive. Depending on the mechanistic details of sex-chromosome drive, Distorter’s spread can additionally facilitate transitions between XY and X0 sex determination. Our results provide a proof of principle that stretches the current understanding of segregation modifier and sex allocation theory. Moreover, we identify alternative evolutionary trajectories that could also lead to remote control drive and discuss its potential applications in developing synthetic sex-ratio-distorting elements for use in pest management, for example.
The shibirets4 mutation causes temperature sensitive paralytic and lethal phenotypes in the Queensland fruit fly, Bactrocera tryoni
35094Anzu Okada, Mamoru Okamoto, Thu N.M. Nguyen, et al., Insect Science, 2025-09-01 19:43:43.
Bactrocera tryoni, the Queensland fruit fly, is among the most damaging insect pests to the Australian horticultural industry as larvae infest ripening fruits or vegetables prior to harvest. Genetic biocontrol using Sterile Insect Technique (SIT) programs have been used to successfully suppress populations, via mass release of factory-reared sterile males that mate with wild females. Bi-sex flies are currently used for releases, although the efficiency of these control programs could be improved through using genetic sexing strains that eliminate females early during development, as they are not required for SIT. Here we used CRISPR/Cas9 mutagenesis to modify two nucleotides in the B. tryoni gene shibire, which created a proline to serine amino acid substitution and produced a temperature sensitive phenotype. Shibire is an essential GTPase required in endocytosis and synaptic vesicle recycling, and classical mutagenic screens in the vinegar fly Drosophila melanogaster previously identified temperature sensitive alleles including shits4 that results in adult paralysis. In B. tryoni, the shits4 mutant strain exhibited similar adult paralytic phenotypes when exposed to high temperatures, as well as temperature dependent lethality at egg, larval and pupal stages when subjected to heat treatment above standard rearing temperatures. These temperature sensitive phenotypes could be adapted to develop a SIT genetic sexing strain for conditional elimination of females prior to sterile releases, to improve efficiency and reduce costs.
Spindle checkpoint can secure additional cheating time for selfish expanded centromeres
35092Walton, R. Zaak et al., Current Biology, 35:3687-3696. 2025-09-01 19:39:54.
Expanded centromeric satellite repeats can violate Mendel’s law of segregation by preferentially segregating to the egg. In mice, these selfish centromeres enrich microtubule destabilizers at pericentromeres to detach from the spindle and flip toward the egg side of the meiotic spindle, thereby achieving preferential segregation. However, despite the consistent enrichment of destabilizers upon centromere expansion, such enrichment alone is insufficient to drive the preferential retention of expanded centromeres, suggesting a missing component in understanding their non-Mendelian segregation. Here, we propose that prolonged spindle checkpoint activation is crucial for expanded centromeres to cheat the segregation process by providing sufficient time for them to flip toward the egg side. By experimentally manipulating kinetochore size in a species-specific manner, we found that assembling larger kinetochores triggers robust spindle checkpoint activation, leading to anaphase delay and preferential retention of expanded centromeres in the egg. Comparisons across multiple hybrid mouse models revealed that centromeric satellite asymmetry does not consistently lead to kinetochore asymmetry and anaphase delay, explaining why satellite asymmetry does not always result in the preferential retention of larger centromeres. Altogether, this work highlights the significance of checkpoint activation in exploiting the inherent asymmetry in female meiosis and the distinct responses of kinetochore proteins and microtubule destabilizers to centromere expansion.
Comparison of the standard and boosted sterile insect techniques for the suppression of Aedes albopictus populations under semi-field conditions
35085Marlène Dupraz, Renaud Lancelot, Gorgui Diouf, et al., Parasite, 32. 2025-08-28 18:38:54.
Innovative control tools are needed against Aedes mosquitoes. The boosted sterile insect technique (bSIT) consists of treating sterile males with a biocide prior to their release to contaminate larval habitats. We compared the efficacy of SIT and boosted SIT to prevent the emergence of adult Aedes albopictus in large cages. We tested two sterile-to-fertile male ratios: 5:1 (SIT5) and 1:1 (SIT1), with and without pyriproxyfen enhancement (bSIT or SIT). The eggs were collected in ovitraps and the immature stages were monitored until adult emergence or up to 15 days after hatching to estimate the relative risk (RR) of adult emergence compared to the control category. The concentration of pyriproxyfen in the ovitrap water did not change when sterile males were released with females or alone (χ2 = 0.99, df = 1, p = 0.547). This concentration was higher when the sterile-to-fertile male ratio was increased from 1:1 to 5:1: χ2 = 18.8, df = 1, p = 0.006. All four treatment categories were effective in suppressing mosquito populations. With a relative risk RR = 0.194 95% CI [0.128; 0.275], SIT5 was the most effective. Boosted SIT was not as effective as SIT. However, bSIT1 (RR = 0.418 [0.351; 0.492]) and bSIT5 (RR = 0.512 [0.431; 0.596]) were equally effective. Boosted males directly vectored pyriproxyfen to breeding sites. Boosted SIT was more effective than SIT alone with a low sterile-to-fertile male ratio. Under operational conditions, it could be initially deployed to suppress the target population and then switched to standard SIT.
Growth and development of two predator species fed a diet of genetically engineered mosquitoes
35081Egan, C.M., Chamberland, L., Ditter, R.E. et al., Parasites Vectors, 18. 2025-08-28 16:18:12.
Genetically engineered mosquitoes (GEMs) with gene drives have been developed for malaria control but remain untested in natural environments. Upon release, GEMs are expected to modify or replace wild-type counterparts, potentially uniquely interacting with nontarget organisms (NTOs). Concerns exist over possible negative effects on NTOs and broader ecological harm. Predators consuming GEMs represent a group that interacts closely with these modified mosquitoes. Here, we examine the effect of GEM and wild-type Anopheles coluzzii diets on the growth of two predator species: the aquatic mosquitofish (Gambusia affinis) and the terrestrial bold jumping spider (Phidippus audax). Gambusia affinis was fed lyophilized gravid mosquitoes, and growth was measured using length and mass. Phidippus audax was fed live semi-gravid mosquitoes, with growth tracked via eye size, body size, and mass. No adverse effects were found in either predator species fed GEM diets. Gambusia affinis showed no significant growth differences between diet groups. However, P. audax that were fed GEMs consumed more mosquitoes, grew larger, and matured faster. Differences in predator growth rate suggest that GEMs’ nutritional content is similar to that of wild-type mosquitoes, but that they may be more vulnerable to predation. Further research is needed to explore whether GEM visual or behavioral traits increase their susceptibility to predators.
Emerging challenges for mosquito-borne disease control and the promise of symbiont-based transmission-blocking strategies
35064Gao H, Hu W, Cui C, Wang Y, Zheng Y, Jacobs-Lorena M, et al., PLoS Pathog, 21. 2025-08-26 17:16:49.
Mosquitoes serve as vectors for a variety of pathogens that cause life-threatening diseases, such as malaria, dengue, Zika, and yellow fever. With the rise of antimalarial drug resistance and a lack of therapeutics or prophylactics for dengue and Zika, current disease control strategies rely heavily on mosquito population management. However, the effectiveness of conventional approaches is increasingly compromised, highlighting an urgent need for innovative tools to combat mosquito-borne diseases. One promising strategy for blocking the transmission of these diseases is to populate mosquitoes with anti-pathogen gut symbionts. Here, we discuss the major challenges facing current mosquito-borne disease control efforts and explore how mosquito gut microbiota-based control strategies may address them. We highlight recent advances that may accelerate field applications and offer perspectives on future directions and the translational potential of symbiont-based strategies for mitigating mosquito-borne disease transmission.
Genetic control strategies for population suppression in the Anopheles gambiae complex: a review of current technologies
35055Alekos Simoni, Ignacio Tolosana, Federica Bernardini, Current Opinion in Insect Science, 2025-08-25 20:42:10.
Malaria continues to pose a critical public health threat, with mosquitoes from the Anopheles gambiae complex acting as the main vectors of the disease in sub-Saharan Africa, where approximately 95% of malaria-related deaths occur. Despite significant advancements in vector control, such as insecticide-treated bed nets and indoor spraying, the effectiveness of these interventions is increasingly compromised by various challenges, including rising levels of insecticide and pathogen resistance, mosquito behavioural adaptations, and persistent funding gaps. In this context, genetic vector control strategies have shown considerable promise, primarily based on findings from controlled laboratory studies. This review explores the development of these genetic approaches within the Anopheles gambiae complex and outlines future directions for their advancement and potential integration into malaria control efforts.
Effectiveness of the sterile insect technique in controlling Aedes albopictus as part of an integrated control measure: evidence from a first small-scale field trial in Switzerland
35042Parrondo Monton, D., Ravasi, D., Campana, V. et al., Infect Dis Poverty, 14. 2025-08-24 16:54:24.
The invasive Asian tiger mosquito (Aedes albopictus) poses growing health risks across Europe. In Switzerland, a preliminary field trial was conducted to assess the feasibility of integrating the sterile insect technique (SIT) into existing integrated vector management (IVM), which includes breeding site removal and application of biological larvicides. SIT involves repeated releases of irradiated sterile males, which mate with wild females, producing non-viable eggs and leading to population decline. Following a preliminary release test in 2022, a small-scale SIT trial took place in 2023 in Morcote, Switzerland. Approximately 150,000 sterile males were released weekly over a 45-hectare area throughout the entire mosquito activity season, from May to September. This SIT area also received routine IVM. Population dynamics were compared with a control area where only IVM was applied. Monitoring included egg counts, hatch rates, and adult female densities. Generalized additive mixed-effects models (GAMM) and generalized additive models (GAM) accounted for spatial, temporal, and random effects. Model selection used AIC, BIC, and Chi-square tests (significance at 5%). The SIT-treated area showed a significant mosquito population reduction. Egg counts dropped by 57% (GAMM regression coefficient: − 0.8513, P < 0.001), with temporal patterns differing between SIT-treated and control areas (P < 0.001). Egg hatch rates were also lower in the SIT area, with odds of hatching reduced by 1.24 log-odds units (P < 0.001). Adult female densities declined by 66% (regression coefficient: − 1.0818, P < 0.001). Spatial GAMs revealed heterogeneous effects: up to 90% egg reduction in the western release area, while the eastern edge, bordering untreated zones, showed up to 300% higher egg counts. Similar spatial trends were observed for hatch rates and adult females (P < 0.01). These findings highlight both the overall effectiveness of SIT and the influence of mosquito immigration on spatial patterns. This trial demonstrated the potential of SIT as a complementary tool in Swiss vector control. Public interest and acceptance were high. To improve cost-effectiveness, further optimization of male production, sterilization, transport, and release processes is needed. Continued implementation over multiple seasons is recommended to enhance long-term effectiveness.
Field Performance of a Self-Limiting, Genetically Engineered Fall Armyworm for Biological Pest Management
35180Reavey Catherine E. , Domingues Felipe A. , Ercit Kyla, et al., Sec. Pest Management, 7. 2025-08-21 14:28:43.
The fall armyworm is one of the most globally significant agricultural pests, damaging corn, sorghum and other crops central to food production. It has developed resistance to several classes of chemical insecticides and, more recently, insect-resistant ‘Bt’ biotech corn varieties. As Bt varieties constitute the great majority of corn acreage in Brazil, proactive resistance management strategies are required to protect the durability of insecticidal efficacy of those cultivars. Previously, we reported on the development of a ‘self-limiting’ fall armyworm strain, called OX5382G, which – after release in the field – is engineered to suppress populations of fall armyworm and manage resistance to Bt crops in treated populations of this pest. Here, we build on this work by carrying out contained studies to empirically assess the pest suppression and resistance management benefits of releasing OX5382G males. We also report on the first open field releases of the OX5382G self-limiting strain in Brazil. Following commercial biosafety approval of this strain by Brazilian government regulators, deployment-relevant OX5382G male performance was then assessed in larger, operational trials in Brazil. Pest suppression and resistance management benefits were demonstrated in contained studies. In the first open field releases, OX5382G males showed comparable performance with wild-type counterparts in terms of dispersal and mating ability. In the subsequent larger, farm-scale trials in Brazil, OX5382G mated effectively in the field and we demonstrated that relatively modest release rates can achieve over-flooding ratios expected to exert suppression and/or resistance management. All assessments to date suggest that self-limiting fall armyworm is a promising future tool for managing fall armyworm and extending the durability of Bt crops’ effectiveness against damaging lepidopteran pests.
Conditional expression of Cas9 and dCas9 in Lucilia cuprina reveals dCas9-associated lethality
35027Alexis Kriete, Tatiana Basika, Rossina Novas, et al., bioRxiv, 2025-08-17 19:42:28.
Conditional sex transformation systems are promising tools in the fight against insect pests. In this study, we developed and tested CRISPR-based, tetracycline-repressible sex transformation strains in the Australian sheep blowfly, Lucilia cuprina. Two CRISPR effector molecules, Cas9 and dCas9, were employed to target the sex-determining gene transformer with the goal of turning female blowflies into males. The Cas9 version of the system induced robust knockout of a visual marker gene but failed to trigger sex transformation without external provision of transformer-targeting sgRNAs. Furthermore, we found that dCas9 expression was linked to several deleterious phenotypes, including developmental delays, reduced body weight, and death. Our study provides the first proof-of-concept conditional CRISPR systems in L. cuprina, and suggests that while dCas9 is toxic at high levels in this species, Cas9 is well-tolerated and may be able to induce sex transformation with minor modifications to the system.
Novel stressors and trait variation determine X-linked meiotic drive frequency
35021Fisher Adam M., White Nicola, Bonsall Michael B., Price Tom AR. and Knell Robert J., Proc. R. Soc. B., 292. 2025-08-13 16:09:01.
Sex ratio meiotic drive alleles bias their transmission by impairing the viability of non-drive gametes, leading to skewed population sex ratios. Despite theoretical predictions that drive alleles should reach fixation causing population extinction, meiotic drive persists at intermediate frequencies in wild populations, though the reasons for this are unclear. Here, we investigate how novel environmental stress and genotype-specific fitness costs contribute to drive frequency. Using a suppression-free X-linked meiotic drive system in Drosophila pseudoobscura, we exposed flies to varying doses of the pesticide permethrin and measured mortality and fecundity across genotypes. We found that drive-bearing males (SR) and drive-homozygous females (SRSR) exhibited heightened mortality, both in the presence and absence of pesticide, while heterozygous (SRST) females exhibited superior fecundity. Using a mathematical model parametrized with our empirical findings, we explored the long-term population dynamics of meiotic drive under different conditions. Our model predicts that drive frequency has a concave relationship with pesticide dose and is strongly modulated by genotype-specific female fecundity. These results suggest that novel environmental stressors and drive-induced fitness effects play key roles in determining meiotic drive frequencies. Our findings improve our understanding of drive frequencies in the wild and have direct implications for drive-based pest control.
Centromeres drive and take a break
Talbert, P.B., Henikoff, S., Chromosome Res, 33. 2025-08-11 14:50:34.The identification of CENPA, CENPB, and CENPC by Earnshaw and Rothfield 40 years ago has revealed the remarkable diversity and complexity of centromeres and confirmed most seed plants and animals have centromeres comprised of complex satellite arrays. The rapid evolution of centromeres and positive selection on CENPA and CENPC led to the centromere drive model, in which competition between tandem satellite arrays of differing size and centromere strength for inclusion in the egg of animals or megaspore of seed plants during female meiosis drives rapid evolution of centromeres and kinetochore proteins. Here we review recent work showing that non-B-form DNA structures in satellite centromeres make them sites of frequent replication fork stalling, and that repair of collapsed forks by break-induced replication rather than unequal sister chromatid exchange is likely the primary mode of satellite expansion and contraction, providing the variation in satellite copy number that is the raw material of centromere drive. Centromere breaks at replication, rather than errors at mitosis, can account for most centromere misdivisions that underlie aneuploidies in cancer.
Drive, suppression, and escape from suppression of a selfish chromosome
35016Jackson Taylor Ridges, Jackson Bladen, Robert L. Unckless, Nitin Phadnis, bioRxiv, 2025-08-11 14:46:50.
Meiotic drivers are selfish chromosomes that are predicted to spark a rapid intragenomic arms-race with their suppressors. However, the long-term persistence of unsuppressed selfish chromosomes in natural populations violates these theoretical expectations. The Drosophila pseudoobscura Sex-Ratio (SR) chromosome exemplifies this problem, sometimes referred to as the ancient gene drive paradox. Here, we reconstruct the evolutionary history of this SR chromosome and show that its genetic architecture and complexity has been shaped by a history of drive, suppression, and escape from suppression. Our results indicate that the current lack of resistance to the SR chromosome represents a transient condition awaiting the emergence of new suppressors.
Genome Editing in Insect Pest Control: Importance, Strategies, and Future Implications
35011Ipsita Samal, Tanmaya Kumar Bhoi, Deepak Kumar Mahanta, Ansh Raj, J. Komal, Alagesan Keerthana, Vinod Kumar Dubey, Genome Editing for Pest Management, 2025-08-06 11:45:12.
Genome editing is a cutting-edge tool in biotechnology which brought about substantial changes in a variety of areas, including agriculture and pest control. As properly managing insect pests is critical for protecting food supplies and ensuring produce security, insect species frequently cause severe problems by destroying crop production, resulting in significant financial losses, food scarcity, and insufficiency. Innovative breakthroughs in pest management technology have lately resulted in the replacement of traditional chemical pesticide applications with environmentally safe and non-polluting interventions. Genome editing has the potential to transform pest control by providing precise and targeted therapies for insect pests that can be managed permanently. Researchers have discovered that genome editing methods have created new possibilities for improving food safety, agricultural productivity, and sustainable agriculture affected by pests. Scientists may now offset insect-related shortcomings with creative ways and strategies that ensure environmentally friendly and sustainable farming practices and environmental preservation, thanks to the application of genome editing tools. This chapter focuses on the use of these state-of-the-art technologies in genome editing tools such as ZFN, TALEN, and CRISPR/Cas9 enables us to assess the viability of insect control strategies, that provide significant promise for next-generation approaches to several major pest management problems and allow the insertion of precisely tailored modifications into the genetic composition of pests. To fully utilize the technology and specifically its implications for more efficient management of insect pests, study, analysis, and collaboration across many sectors are essential, which has been centralized in the current chapter.
Sequence mismatch between gene-drive and target-site flanking regions significantly impairs homing efficiency in Culex quinquefasciatus
35007Tim Harvey-Samuel, Rajdeep Kaur, Philip T Leftwich, et al., bioRxiv, 2025-08-04 11:03:26.
CRISPR/Cas9-based homing gene-drives (homing-drives) hold enormous potential as control tools for mosquito disease-vectors. These genomically-encoded technologies spread themselves through target populations by creating double-stranded DNA breaks on homologous chromosomes, into which the homing-drives are copied (homed). Homing is dependent on sequence homology between the genomic regions flanking the transgene insertion and the break site. Homing efficiency (i.e. copying rate) substantially impacts the power of these systems: less efficient homing-drives spread slower, have fewer applications and are more resistance-prone. Understanding what influences homing-drive efficiency is therefore vital to the successful use of these technologies. Here we report a novel mechanism by which a homing-drives efficiency can be significantly impaired by natural sequence variation within a population into which it is spreading. Using a kmo-targeting split homing-drive in the West Nile virus mosquito Culex quinquefasciatus, we found that target-site heterology (sequence mismatch between the genomic regions flanking the target cut-site and the homing-drive transgene) of less than 10% reduced homing efficiency by up to 54%. While substantial research effort has been dedicated to increasing homing-drive efficiency through optimisation of within-construct components, our results highlight that the real-world efficacy of these systems may in part depend on variation beyond these controllable factors.
Spatiotemporal complexity in interacting wild and sterile mosquito populations
35005Mandal, G., Guin, L.N. & Chakravarty, S., Nonlinear Dyn, 2025-08-04 08:39:42.
In the present exploration, a mosquito population model is investigated that incorporates a non-linear, saturated release rate for sterile mosquitoes. The model framework leverages a reaction-diffusion system to generate spatiotemporal patterns. A thorough theoretical analysis is conducted to explore the model’s feasible equilibria, focusing on the phenomenon of bistability. Subsequently, the stability, instability, and potential bifurcation scenarios are examined rigorously. Each identified bifurcation is then utilized to elucidate the complex dynamical behaviour of the system. The entire parameter space is systematically partitioned by simultaneously varying two key parameters. This partitioned space can then be further analyzed in conjunction with one and two-parameter bifurcation diagrams. This approach facilitates a deeper understanding of the system’s dynamics within each identified region. In two dimensions (2D), the evolution of diffusion-driven pattern formation is presented for various scenarios, including spots, stripes, labyrinthine structures, combinations of stripes and holes, and hole replication. These spatial patterns are demonstrated to be influenced by critical system factors associated with the concept of Turing space. Sensitivity analysis reveals that the number of wild offspring produced per mating event is the most sensitive parameter within the model. Moreover, the present investigation admits dynamical codimension one and two bifurcations concerning the induced most sensitive parameter. The theoretical findings are consistently validated and corroborated by numerical simulations, which are further employed to evaluate the biological implications of the theoretical results.
Suppression of sex-ratio drive in Drosophila subobscura
35233Sophie Lyth, Tom Gill, Andri Manser, et al., Evolution, 2025-07-30 15:46:21.
Selfish genetic elements enjoy an evolutionary advantage by enhancing their own transmission to offspring, and their genetic suppressors are favored when they re-establish fair inheritance patterns. Here, we study an X-linked sex ratio drive system (SR) in Drosophila subobscura, which kills Y-bearing sperm of SR males, resulting in the over-transmission of the SR chromosome and a strong female bias in their offspring. We surveyed D. subobscura populations in North Africa, which naturally harbor SR, and found that suppression occurs in ∼13.5% of wild-derived lines. We characterize this suppression phenotype through a series of crossing experiments, including multigenerational introgression of SR chromosomes into a suppressing genetic background. We show that introgression can restore normal offspring sex ratios or, in some cases, result in an excess of male offspring. This suppression appears to be a multilocus trait, involving autosomes and the Y chromosomes. Suppression of SR fails to ameliorate all costs of drive, with fully suppressed SR-carrying males having depressed fertility and low offspring egg hatch rates. Further examination of internal male reproductive organs using microscopy suggests that suppressed SR males also have abnormal testes. These factors may explain why the suppression fails to reach high frequencies, despite the strong advantage of suppressing SR.
Threshold-dependent improvement in sex separation efficiency by NaCl pretreatment of larval–pupal mixtures in mass-reared Aedes albopictus
34996Yan Sun, Junyan Zhang, Keqing Zheng, et al., Pest Science Management, 2025-07-30 12:54:37.
The removal of female mosquitoes is a critical requirement in sterile insect technique (SIT) for mosquito control. Improving the efficiency and accuracy of sex sorting is therefore vital. Previous studies have demonstrated that treating larval–pupal mixtures with a 15% sodium chloride (NaCl) solution prior to the sex sorting process reduces female contamination in Aedes mosquitoes. However, the effects of NaCl on Aedes albopictus mosquito biology and its practical application in production facilities remain insufficiently explored and warrant further investigation. Exposure of larval–pupal mixtures to 15% NaCl for 60 min led to 100% larval mortality via osmotic imbalance and intestinal tissue damage, while pupae remained unaffected due to their impermeable cuticle. Males emerging from treated pupae exhibited comparable emergence, longevity, and flight ability to controls, indicating no adverse effect on male quality. NaCl pretreatment significantly improved sorting efficiency and reduced female contamination in manual sorting, achieving a 3.9-fold reduction in adult-stage contamination. Although automatic sorters increased throughput, reductions in female contamination were not statistically significant. Importantly, the sorting benefits of NaCl treatment were threshold-dependent and most evident at larger processing scales. NaCl pretreatment is a simple, scalable, and biologically safe strategy to enhance sex separation in Ae. albopictus mass production. It is particularly advantageous under high-throughput conditions and preserves male fitness, supporting the stringent quality standards required for successful SIT-based mosquito control.
CRISPR-GPT for agentic automation of gene-editing experiments
35077Qu, Y., Huang, K., Yin, M. et al., Nat. Biomed. Eng, 2025-07-30 12:34:29.
Performing effective gene-editing experiments requires a deep understanding of both the CRISPR technology and the biological system involved. Meanwhile, despite their versatility and promise, large language models (LLMs) often lack domain-specific knowledge and struggle to accurately solve biological design problems. We present CRISPR-GPT, an LLM agent system to automate and enhance CRISPR-based gene-editing design and data analysis. CRISPR-GPT leverages the reasoning capabilities of LLMs for complex task decomposition, decision-making and interactive human–artificial intelligence (AI) collaboration. This system incorporates domain expertise, retrieval techniques, external tools and a specialized LLM fine tuned with open-forum discussions among scientists. CRISPR-GPT assists users in selecting CRISPR systems, experiment planning, designing guide RNAs, choosing delivery methods, drafting protocols, designing assays and analysing data. We showcase the potential of CRISPR-GPT by knocking out four genes with CRISPR-Cas12a in a human lung adenocarcinoma cell line and epigenetically activating two genes using CRISPR-dCas9 in a human melanoma cell line. CRISPR-GPT enables fully AI-guided gene-editing experiment design and analysis across different modalities, validating its effectiveness as an AI co-pilot in genome engineering.
How population control of pests is modulated by density dependence: The perspective of genetic biocontrol
34993Cole D. Butler, Alun L. Lloyd, Journal of Theoretical Biology, 2025-07-30 11:07:06.
Managing pest species relies critically on mechanisms that regulate population dynamics, particularly those factors that change with population size. These density-dependent factors can help or hinder control efforts and are especially relevant considering recent advances in genetic techniques that allow for precise manipulation of the timing and sex-specificity of population suppression. Despite this importance, density dependence is often poorly characterized owing to limited data and an incomplete understanding of developmental ecology. To address this issue, we construct and analyze a mathematical model of a pest population with a general control under a wide range of density dependence scenarios. Using this model, we investigate how control performance is affected by the strength of density dependence. By modifying the timing and sex-specificity of the control, we tailor our analysis to simulate different pest control strategies, including conventional and genetic biocontrol methods. We pay particular attention to the latter as case studies by extending the baseline model to include genetic dynamics. Finally, we clarify past work on the dynamics of mechanistic models with density dependence. We find substantial differences in control performance for differing strengths of density dependence, with populations exhibiting strong density dependence being most resilient to suppression. However, these results change with the size and timing of the control load, as well as the target sex. Interestingly, we also find that the strength of density dependence affects population invasion by certain genetic biocontrol strategies. While the model is parameterized using the life history traits of the yellow fever mosquito, Aedes aegypti, the principles developed here apply to many pest species. We conclude by discussing what this means for pest population suppression moving forward.
Knowledge, attitude, and practice (KAP), and acceptance and willingness to pay (WTP) for mosquito-borne diseases control through sterile mosquito release in Bangkok, Thailand
34991Kittayapong P, Ninphanomchai S, Jalichandra N, Sringernyuang L, Sherer P, Meemon N, PLoS Negl Trop Dis, 19. 2025-07-30 11:03:04.
A questionnaire survey was conducted in seven communities in Bangkok, Thailand to obtain baseline information on knowledge, attitudes and practices (KAP) related to mosquito-borne diseases, i.e., dengue, chikungunya and Zika, including mosquito vectors and how to control them. The questionnaire also asked about the acceptance and willingness to pay (WTP) for sterile mosquitoes used in controlling mosquito populations. Our results showed that, from a total of 400 sampling households, about 85% of participants were familiar with dengue and its mosquito vectors, as well as their prevention and control. Furthermore, participants with lower ages and higher incomes had more knowledge on mosquito vectors (p < 0.05). Even though the majority of participants did not have any knowledge on sterile mosquito release, they showed a positive perception about it. However, more than half of them were not willing to pay for sterile mosquitoes, since they would like to receive them as public support from the government. If they were to pay, the cost that they could afford was 1–2 THB (~US$ 0.03- 0.06) per sterile mosquito. These findings should be useful for public health authorities when planning to apply the sterile mosquito release as an alternative mosquito control approach in Bangkok, Thailand.
Implications of successive blood feeding on Wolbachia-mediated dengue virus inhibition in Aedes aegypti mosquitoes
34989Johnson, R.M., Breban, M.I., Nolan, B.L. et al., Nat Commun, 16. 2025-07-30 10:55:57.
Wolbachia is a promising strategy to inhibit dengue virus (DENV) transmission by Ae. aegypti mosquitoes. Laboratory studies assessing DENV inhibition by Wolbachia typically have not considered natural frequent mosquito blood feeding behavior. Here, we determine the impact of successive feeding on DENV-2 transmission by Ae. aegypti in the presence or absence of Wolbachia (wAlbB and wMelM strains). We show that successive feeding shortens the extrinsic incubation period (EIP) in wildtype (WT; without Wolbachia) and wAlbB mosquitoes through enhanced dissemination. Feeding empirical data into models showed that successive feeding increases the probability of WT and wAlbB mosquitoes surviving beyond the EIP. Importantly, the more epidemiologically relevant comparison of the odds of wAlbB mosquitoes surviving beyond the EIP relative to WT, reveals a larger impact of successive feeding on WT than wAlbB. This indicates a strong inhibitory effect of Wolbachia even in the context of natural frequent mosquito blood feeding behavior.
Coproducing a Technology Readiness Level framework for non-persistent genetic biocontrol of aquatic invasive species
34984Julie Badger, Rex Alirigia, Isabel Ameli, et al, Journal of Environmental Management, 391. 2025-07-24 10:00:28.
Developing and implementing novel pest control technologies requires coordination and communication between technology developers, funding agencies, federal and state regulators, and early technology adopters. Efficient communication is particularly important for first-in-class technologies. Misunderstandings or lack of communication may hinder social engagement, jeopardize regulatory approval, decrease utility of the technology, deter public adoption, or compromise risk mitigation approaches. We, a team of diverse stakeholders in aquatic invasive species (AIS) control, here propose a shared language for discussing the development of non-persistent genetic biocontrol methods. Specifically, we adapted the existing Technology Readiness Level framework to apply to the development of non-persistent genetic biocontrol for invasive Cyprinus carpio (common carp) as a model case. The result of this effort is a tool for designing responsible technology development of a promising new class of pest management tools.
Driving a protective allele of the mosquito FREP1 gene to combat malaria
34980Li, Z., Dong, Y., You, L. et al., Nature, 2025-07-24 09:46:46.
Malaria remains a substantial global health challenge, causing approximately half a million deaths each year1. The mosquito fibrinogen-related protein 1 (FREP1) is required for malaria parasites to infect the midgut epithelium2. The naturally occurring FREP1Q allele has been reported to prevent parasite infection, while supporting essential physiological functions in the mosquito3. Here we generate congenic strains of Anopheles stephensi, edited to carry either the parasite-susceptible FREP1L224 or the putative-refractory FREP1Q224 alleles. The FREP1Q224 allele confers robust resistance to infection by both human and rodent malaria parasites, with negligible fitness costs. The protective FREP1Q224 allele can be efficiently driven into FREP1L224 mosquito populations using a novel linked allelic-drive system that selectively replaces the L224 codon with the parasite-refractory Q224 allele, thereby rendering populations refractory to parasite infection. This antimalaria drive system provides a novel genetic approach to aid in malaria elimination efforts.
Decoding and engineering temperature-sensitive lethality in Ceratitis capitata for pest control
34970R.A. Aumann, G. Gouvi, M. Gregoriou,T. Rehling, G. Sollazzo, K. Bourtzis, and M.F. Schetelig, Proceedings of the National Academy of Sciences, 122. 2025-07-10 10:38:52.
The Sterile Insect Technique (SIT) is a species-specific and environmentally friendly method for effectively controlling pest insect populations based on releasing reared, sterile insects into infested areas. Sex sorting in rearing facilities, enabling male-only releases, is necessary to ensure SIT programs are efficient, cost-effective and, in case of mosquito control, also safe. This can be greatly facilitated by genetic sexing strains (GSS), exhibiting sex-specific phenotypic markers. However, the development of GSS remains challenging. The construction of a temperature-sensitive lethal (tsl)-based GSS in the Mediterranean fruit fly (Ceratitis capitata) over three decades ago was considered a major breakthrough for SIT programs but was never successfully replicated in other pests. After over 30 y of research, we have pinpointed a specific mutation in the C. capitata lysine--tRNA ligase (Lysyl-tRNA synthetase, LysRS) gene responsible for the tsl phenotype. Introducing this specific mutation into a wild-type strain produced full embryonic lethality under heat stress, replicating the original mutant phenotype. The random integration of a LysRS minigene reversed this effect. The high conservation of LysRS among insects suggests that tsl-based GSS could be expanded to multiple pest species and extend applications of SIT programs for disease prevention and the protection of agriculture.
CRISPR technologies for the control and study of malaria-transmitting anopheline mosquitoes
34964Smidler, A.L., Akbari, O.S., Parasites Vectors, 18. 2025-07-08 13:44:43.
Malaria is one of the deadliest diseases on the planet, killing approximately 600,000 people annually, and is transmitted by the bite of an anopheline mosquito. Anophelines, and the diseases they transmit, have changed the course of history and the fate of nations, and their successful control promises to end the transmission of malaria. With the advent of clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) technologies, the study and control of these deadly pests have been revolutionized. As the release of genetically modified anophelines is being considered, here we outline the advances in CRISPR/Cas9 technologies and how they have revolutionized the study of anopheline basic biology and the development of innovative vector control strategies. We outline the major findings of CRISPR-based basic biological research into traits relevant for vector control including, but not limited to, olfaction, chemosensation, neurobiology, and reproduction. Further, we summarize the advancements in CRISPR-based innovative vector control strategies, such as the precision-guided sterile insect technique (pgSIT), inherited female elimination by genetically encoded nucleases to interrupt alleles (IFEGENIA), X-shredder, Y-linked editors, and gene drives. All in all, this review summarizes the basic biological and vector control research undertaken using CRISPR since its advent approximately a decade ago.
Assessing the impact of the Wolbachia-based control of malaria
34962Zhuolin Qu, Lauren M. Childs, Mathematical Biosciences, 2025-07-08 13:34:58.
Malaria remains a significant infectious disease globally, causing hundreds of thousands of deaths each year. Traditional control methods, such as disease surveillance and mosquito control, along with the development of malaria vaccines, have made strides in reducing the disease’s impact, but new control methods are urgently needed. Wolbachia is a natural bacterium that can infect mosquitoes and reduce their ability to transmit diseases. While initially used to control dengue fever, recent research explored its potential for malaria control. In this study, we develop and analyze a novel mathematical model to assess the potential use of Wolbachia-based strategies for malaria control. The model describes the complex Wolbachia transmission dynamics among mosquitoes and incorporates key features of malaria transmission in humans with dynamical immunity feedback. We derive the basic reproduction number of the malaria disease transmission, which depends on the prevalence of Wolbachia in mosquitoes. Our findings reveal bifurcations in both Wolbachia transmission among mosquitoes and malaria transmission in humans, suggesting the potential for malaria elimination through Wolbachia-based interventions. The sensitivity analysis identifies the important parameters for the basic reproduction number and for malaria reduction and elimination. We numerically explore the integration of Wolbachia and other malaria controls. When control focuses on reducing the malaria burden in humans, there is a substantial rebound in malaria prevalence following the intervention in humans, and our results suggest post-Wolbachia malaria control leads to the greatest reduction in total days of infection. When Wolbachia release is integrated with pre-release mosquito control, there is a comparably large reduction in total days of infection if pre-release mosquito control occurs only a few days before Wolbachia release.
Dynamical analysis of a nonlocal delays spatial malaria model with Wolbachia-infected male mosquitoes release
34960Liping Wang, Runqi Liu, Yangyang Shi, Electronic Research Archive, 33:3177-3200. 2025-07-08 13:27:46.
Malaria continues to pose a considerable threat to global health. This study investigates the use of releasing Wolbachia-infected male mosquitoes as a method to mitigate the spread of malaria. We have formulated a reaction-diffusion model with nonlocal delays that includes the Wolbachia release strategy. The basic reproduction number R0 is defined within our model framework, serving as a critical threshold parameter that dictates the dynamic behavior of the model. A thorough dynamic analysis of the model reveals that when R0<1, a globally attractive infection-free steady state is established. In contrast, if R0>1, the disease persists uniformly. Numerical simulations are conducted to validate the theoretical results and to further illustrate the effectiveness of the Wolbachia release strategy on transmission and control of malaria. These simulations underscore the potential of using Wolbachia-infected male mosquitoes to significantly reduce spread of malaria.
