Scholarly Literature

This is a database of scholarly literature that concentrates currently on natural and engineered selfish genetic elements (gene drives).  The latest are shown here.
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The role of toxin/antidote genes in the maintenance and evolution of accessory chromosomes in Fusarium

35333
Linnea Sandell, Adrian Forsythe, Anna Mirandola, et al.,  Genetics,  231. 2025-12-31 14:56:39.
The genomic diversity of many fungal species is augmented by accessory chromosomes, which are variably present in individual strains. These genomic regions evolve rapidly, accumulating genes important in pathogenicity but also harbor a significant number of transposable elements. This duality suggests a trade-off: accessory chromosomes provide infection-related benefits while otherwise being deleterious due to their highly repetitive nature and contributions to genomic instability. Despite this, accessory chromosomes often appear to be stably maintained even when strains are grown on media, with no plant host. Previously, we had observed that genes homologous to meiotic drive toxin/antidote proteins from Podospora anserina (Spoks) are abundant on accessory chromosomes in various Fusarium species. Using a functionality screen in yeast, we demonstrate that some of these homologs have active toxin and antidote properties. We propose that these selfish genes could maintain accessory chromosomes during vegetative growth and may influence their spread via parasexual cycles. Finally, as Spok genes are found on the newly described transposable element superfamily Starships, we also present a model for how these transposable elements could play a role in forming accessory chromosomes and regions. These results illuminate a mysterious facet of fungal biology, a key step towards describing the origin, spread, and maintenance of pathogenicity in many fungal species.

Evolutionary persistence and divergence of the tdk killer meiotic driver family

35476
Fan-Yi Zhang, Guo-Song Jia, Jing-Yi Ren, et al.,  bioRxiv,  2025-12-29 18:22:02.
Killer meiotic drivers (KMDs) are selfish genetic elements that achieve super-Mendelian inheritance by selectively eliminating gametes lacking the driver. Although predicted to arise recurrently, KMDs are generally considered evolutionarily ephemeral—going extinct after fixation or host suppression. The identification of tdk1, a single-gene KMD in the fission yeast Schizosaccharomyces pombe, provides a model for studying KMD evolution. Here, we identify two divergent tdk1 homologs (tdk210 and tdk203) from S. cryophilus, a fission yeast species that diverged ∼100 million years ago from S. pombe, as active KMDs. These three KMDs all act via post-germination killing, disrupting chromosome segregation in noncarrier progeny. Notably, they also exhibit striking functional divergences: tdk1, tdk210, and tdk203 are mutually incompatible (showing no cross-resistance), and the latter two act independently of Bdf1/Bdf2—host chromatin proteins required for tdk1 killing. Phylogenetic analyses of the dozens of tdk family genes in Schizosaccharomyces support long-term persistence and rapid evolutionary dynamics of this gene family. Remarkably, homologs in distantly related fungal phyla display genomic and structural similarities to Schizosaccharomyces tdk genes, suggesting a deeply rooted origin of this KMD family in fungi. Our findings reveal that a single KMD family can undergo repeated functional innovation—generating mutually incompatible variants and rewiring host dependencies—while maintaining a conserved killing mode over deep evolutionary time.

Wolbachia as a transformative tool for mosquito-borne disease control: a comprehensive review of mechanisms, efficacy, and future directions

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Minaei, M. E., Yousefi Nojookambari, N., Ghodraty, M., & Yazdansetad, S.,  Pathogens and Global Health,  2025-12-23 12:15:44.
Mosquito-borne infectious diseases such as dengue, Zika, chikungunya, and malaria continue to pose significant public health challenges worldwide. Traditional control methods, including the use of insecticides and environmental management, have shown limited effectiveness due to insecticide resistance and logistical challenges. Wolbachia-based strategies, which leverage the bacterium’s unique ability to manipulate mosquito reproduction and block pathogens, present a promising, albeit not universally applicable, method for reducing the transmission of mosquito-borne diseases. Field trials have demonstrated significant but variable efficacy. This systematic review synthesizes the latest findings on Wolbachia-based interventions, focusing on their mechanisms, efficacy, and potential for large-scale implementation. We conducted a comprehensive literature search across multiple databases, including PubMed, Scopus, and Web of Science, to identify relevant studies published between 1990 and 2025. Our review highlights the promising results of Wolbachia-based strategies in reducing mosquito populations and disease transmission, while also addressing the challenges and limitations of this approach. We conclude that Wolbachia-based strategies hold great potential for revolutionizing mosquito-borne disease control, but further research and careful consideration of ecological and ethical implications are necessary for their successful implementation.

Analysis of a household-scale model for the invasion of Wolbachia into a resident mosquito population

35327
Barlow, A., Penington, S. & Adams, B.,  Journal of Mathematical Biology,  92. 2025-12-22 12:18:25.
In areas infested with Aedes aegypti mosquitoes it may be possible to control dengue, and some other vector-borne diseases, by introducing Wolbachia-infected mosquitoes into the wildtype population. Thus far, empirical and theoretical studies of Wolbachia release have tended to focus on the dynamics at the community scale. However, Ae. aegypti mosquitoes typically dwell in and around the same houses as the people they bite and it can be insightful to explore what happens at the household scale where small population sizes lead to inherently stochastic dynamics. Here we use a continuous-time Markov framework to develop a stochastic household model for small populations of wildtype and Wolbachia-infected mosquitoes. We investigate the transient and long term dynamics of the system, in particular examining the impact of stochasticity on the Wolbachia invasion threshold and bistability between the wildtype-only and Wolbachia-only steady states previously observed in deterministic models. We focus on the influence of key parameters which determine the fitness cost of Wolbachia infection and the probability of Wolbachia vertical transmission. Using Markov and matrix population theory, we derive salient characteristics of the system including the probability of successful Wolbachia invasion, the expected time until invasion and the probability that a Wolbachia-infected population reverts to a wildtype population. These attributes can inform strategies for the release of Wolbachia-infected mosquitoes. In addition, we find that releasing the minimum number of Wolbachia-infected mosquitoes required to displace a resident wildtype population according to the deterministic model, only results in that outcome about 20% of the time in the stochastic model; a significantly larger release is required to reach a steady state composed entirely of Wolbachia-infected mosquitoes 90% of the time.

A target product profile for a rapid diagnostic test to monitor mosquito gene drive presence and frequency

35345
Prateek Verma, Sebald Verkuijl, Calvin K. Yee, et al.,  bioRxiv,  2025-12-18 10:23:36.
Malaria remains a major global health challenge, with over 263 million cases and nearly 600,000 deaths reported in 2023, the majority in sub-Saharan Africa. While conventional interventions such as insecticide-treated nets, indoor residual spraying and antimalarial drugs have reduced transmission, progress has stalled due to the limitations of these interventions and the emergence of resistance. Gene drive-modified mosquitoes represent a promising, potentially transformative vector control strategy, capable of spreading malaria-refractory traits or suppressing mosquito populations. Successful field deployment will depend upon monitoring systems to track the presence and frequency of gene drive constructs as they spread and persist. Current molecular surveillance techniques, though effective, are resource-intensive and reliant on laboratory infrastructure and technical competencies. Here, we make the case for a near-universal and low-cost rapid diagnostic test (RDT) designed to detect gene drive mosquitoes in the field, to complement existing surveillance infrastructure. Two use cases are outlined: i) to detect the presence of the drive construct in a new population, and ii) to provide an estimate of drive frequency prior to more accurate laboratory-based measurements. We provide a target product profile for the RDT outlining minimally essential and ideal characteristics, including test procedures, sensitivity, specificity, usability by a range of stakeholders in field settings, and compatibility with pooled testing of mosquito samples. An RDT for gene drive construct detection would support community access and participation in monitoring, enhance regulatory oversight, and promote transparency in field trials, thereby facilitating responsible deployment of gene drive-based malaria interventions.

Strategies to improve the efficiency of homing gene drives with multiplexed gRNAs

35416
Chen, W., Wu, P. & Champer, J.,  BMC Biol,  24. 2025-12-12 16:50:27.
CRISPR homing gene drive holds great potential for pest control, but its success is challenged by the generation of resistance alleles through end-joining repair. Using multiple gRNAs to target adjacent sites within a conserved gene can prevent functional resistance by allowing repeated cleavage events, but poor homology during DNA repair may compromise efficiency. We first assessed the efficiency of single gRNA drives with truncated homology arms in Drosophila melanogaster mimicking a multiplexed system in which only one site is cleaved. Integrating results into a detailed gRNA multiplexing model, we found that efficiency loss was greater than expected. To mitigate this, we evaluated two new strategies: (1) extended homology arms to span all target sites (with mutations in the PAMs to prevent self-cleavage) and (2) a population-level gRNA multiplexing system involving two or more drives, each carrying two gRNAs. Extended homology arms did not result in notable improvement in conversion efficiency, and the extended region could be lost during drive conversion. The population-level multiplexing gRNAs strategy was more promising, though the intentionally mutated PAM also could not be consistently inherited. Simulations of homing suppression drives applying population-level multiplexed gRNAs increased the success rate of population elimination and reduced the time required for suppression. Future drive designs requiring a larger number of gRNAs could potentially be improved. The design relying on extended homology arms may not represent an optimal strategy. However, population-level multiplexing gRNAs could serve as a promising alternative, enhancing efficiency while maintaining tolerance to functional resistance.

Improving Wolbachia-based control programs in urban settings: Insights from spatial modeling

35335
Florez D, Cortez R, Hyman JM, Qu Z,  PLoS Neglected Tropical Diseases,  19. 2025-12-12 11:08:20.
Arboviral diseases remain a major public health concern, particularly in tropical and subtropical regions where mosquito populations thrive. One promising strategy to curb transmission is the release of Aedes aegypti mosquitoes infected with Wolbachia, a bacterium that reduces their ability to spread viruses. However, past large-scale releases have not always been successful, especially in complex urban settings, where restricted access to certain areas often leads to infection establishment failures and wasted resources. To address this, we developed a spatial model that simulates how Wolbachia-infected mosquitoes are established in different urban environments. We also explored strategies to improve their success under constraints on release size and the efficacy level of insecticide used for pre-release interventions. Our findings suggest that targeted releases are most effective in areas with limited mosquito movement without additional insecticide use. In higher-dispersal areas, reducing at least 35% of wild mosquitoes before release significantly improves establishment within nine months. Additionally, distributing releases over 2-5 weekly batches enhances success more than a single large release, even without other interventions. These findings offer practical insights for designing cost-effective and efficient Wolbachia-based mosquito control programs, reducing the burden of mosquito-borne diseases on vulnerable communities.

Homing gene drive strains for genetic suppression of agricultural insect pests

35331
Yadav, Amarish K.; Tarrand, Ariel E.; Scott, Maxwell J.,  Entomologia Generalis,  45:1577 - 1590. 2025-12-04 14:52:03.
Agricultural insect pests cause substantial losses in crop productivity each year. Genetic-based strategies provide economical and environmentally friendly ways to limit pests that reproduce sexually. In contrast to conventional genetic methods (e.g. SIT), homing gene drives (HGDs) are potentially capable of suppressing or modifying an entire pest population in a short period of time after releasing a small number of HGD insects. The advent of CRISPR/Cas gene editing tools has simplified the engineering of gene drives, and the progress made on HGDs in various insects in the recent past is encouraging. However, to date HGDs have been developed and evaluated in only a few agricultural pest species. These drives have been designed to suppress populations by targeting genes essential for female development or fertility. Homing gene drive relies on homology directed repair (HDR) of the Cas9-mediated double-stranded DNA break in germ cells. Consequently, the use of other DNA repair pathways such as non-homologous end joining (NHEJ) and micro-homology mediated end joining (MMEJ) can retard homing. Further, establishment of functional resistant alleles through these end-joining pathways is one of the major challenges associated with HGDs. Development of HGDs in some pest species is challenging due to the technical difficulties of making transgenics. Identification and characterization of germline-specific promoters and other regulatory elements to achieve precise HDR (in early meiosis) can facilitate efficient homing. In this review, we highlight the recent progress made towards developing HGDs in agricultural insect pests with insights gained from studies in model organisms (e.g. Drosophila melanogaster).

A temperature-sensitive CRISPR-Cas12a system for sterile insect technique

35361
Nguyen, C., Omotayo, A.I., Sanz Juste, S. et al.,  Nature Communications,  16. 2025-11-14 11:49:30.
The sterile insect technique (SIT) reduces population numbers by releasing sterile males that produce non-viable progeny. Specifically, CRISPR/Cas9-based precision-guided SIT (pgSIT) generates sterile males through genetic crosses of two transgenic lines: a Cas9 strain and a guide RNA (gRNA) strain targeting male sterility and female viability or infertility. However, pgSIT requires separate maintenance of the two lines and sorting to obtain sterile males, creating possible challenges for scaling. To overcome this, we propose using Cas12a nuclease, which is inoperative at lower temperatures but active at higher temperatures. Here, we develop a Cas12a-based pgSIT system involving a single strain containing both the Cas12a nuclease and gRNAs to induce male sterility and female lethality. This strain can be maintained as a mixed stock of both sexes and only activated by increasing temperature, producing sterile males after just one generation. By reducing the challenges that arise with maintaining two separate lines, this system could offer a scalable alternative for vector control in combating vector-borne diseases.

Variants in Cas9 and nanos regulatory elements modulate activity and reduce resistance allele formation in homing gene drive

35294
Ruizhi Zhou, Jie Du, Nicky R. Faber, Jackson Champer,  bioRxiv,  2025-11-09 18:15:12.
Gene drive is a novel approach for controlling vector borne disease via either population modification or suppression. Even with high efficiency, though, overall drive performance can be reduced by somatic Cas9 expression and by maternal deposition of Cas9, leading to resistance allele formation. The nanos promoter for Cas9 shows very little leaky somatic expression, but it causes high rates of embryo resistance allele formation in Drosophila melanogaster. By truncating the promoter, we reduced rates of embryo resistance to undetectable levels, but germline cutting in females decreased by over half. Germline cutting and successful drive conversion was eventually lost when only the 5′ UTR was present, though males still retained moderate germline drive efficiency. Several additional methods were tested to improve performance, including additional suppressor elements to the 3′ UTR and introns to increase expression level. The most successful of these was the addition of a second nuclear localization signal, which substantially increased activity when coupled with a full-length or truncated nanos promoter. Overall, these experiments show the potential to modulate Cas9 regulatory elements to achieve desired expression for gene drive applications, while also showcasing the difficulty of obtaining an optimal activity profile.

Inhibiting invasive fish reproduction via germ cell xenotransplantation and hybrid lethality

35292
Amano, Y., Baba, H., Kishi, D. et al.,  Scientific Reports,  15. 2025-11-09 17:56:43.
Invasive alien fish constitute a major problem in the conservation of aquatic ecosystems. The most common method of exterminating invasive fish is physical capture by fishing gear; however, it is extremely difficult to eradicate them. Here, we developed a novel methodology to inhibit the reproduction of invasive fish by releasing surrogate males of the same species, which produce sperm of different species, into rivers, allowing them to produce lethal hybrids through natural spawning. This study focused on rainbow trout, an invasive fish that negatively impacts ecosystems worldwide. Since rainbow trout × brown trout hybrids are lethal, surrogate rainbow trout producing brown trout sperm were created by germline stem cell transplantation. Releasing the surrogate males into an experimental river inhabited by wild-type rainbow trout females revealed that they naturally mated and produced lethal hybrid offspring. This is a novel and powerful methodology for eradicating invasive fish.

Integrating mosquito genomics into simulation modeling: Opportunities for better-informed biocontrol

35282
Gordana Rašić, John M. Marshall,  Current Opinion in Insect Science,  2025-11-03 11:25:51.
Mosquito-borne diseases remain a major global health burden, and novel biocontrol tools are quickly advancing from the laboratory to the field. Mathematical models play a central role in evaluating these interventions, yet their predictive accuracy depends on robust parameterization. Population genomics presents a powerful opportunity to address this challenge. Here, we review progress at the interface between mosquito genomics and biocontrol modeling, highlighting how genomic data have informed our understanding of mosquito population structure, standing genetic variation at gene drive target sites, and sources of resurgence for suppressed populations. We also discuss frontiers, including new approaches to quantifying gene flow, mating behaviors, and inbreeding depression, all of which shape intervention outcomes. By tapping this potential to better quantify our understanding of mosquito ecology, modelers can develop context-specific models with better predictive accuracy, supporting efficacy and risk assessment, design of field trials and interventions, and promotion of regulation and public trust.

Synthetic biology approaches to generate temperature-sensitive alleles for the Sterile Insect Technique

35280
Chun Yin Leung, Ernst A. Wimmer, Hassan M. M. Ahmed,  Insect Science,  2025-11-03 11:22:09.
The Sterile Insect Technique (SIT) is an environmentally friendly, sustainable pest control approach, which uses large-scale releases of sterile insects to suppress or eradicate target populations through infertile matings. The efficiency of SIT is enhanced by male-only releases requiring genetic sexing strains (GSSs) that are classically based on selectable recessive visible markers or temperature-sensitive lethal (tsl) mutations and a rescue by a wild-type allele translocated to the male-determining chromosome. The transfer of identified or designed temperature-sensitive alleles might allow the generation of neoclassical GSSs in additional SIT target species. By using precise genome-editing tools, such as CRISPR/Cas, the creation of specific mutations in target genes and the integration of a wild-type copy is feasible without the introduction of foreign DNA. This might ease regulation of neoclassical GSSs, since they are not considered transgenic. However, integration and expression of genes at male-determining loci or chromosomes is not reliably established. Therefore, additional strategies to link temperature-sensitive phenotypes to female development are required, which could be achieved by targeting genes involved in dosage compensation or sex determination. To create temperature-sensitive alleles, rational protein design using advanced modeling and prediction tools to evaluate and tailor the effect of mutations on protein stability and temperature sensitivity can be used. In addition, emerging synthetic biology strategies such as temperature-inducible N-degrons or temperature-sensitive inteins provide powerful tools to generate temperature sensitivity. Such approaches should enable conditional control over proteins causing female lethality or sex conversion and therefore promise straightforward generic approaches to generate GSSs for male-only production in SIT target species.

Effect of male age at the time of irradiation on the sexual performance of sterile Ceratitis capitata males: insights from remating female offspring

35278
Edwin Mauricio Ramírez-Santos, Pedro Alfonso Rendón Arana, et al.,  Insect Science,  2025-11-03 11:19:51.
The Sterile Insect Technique (SIT) is an effective strategy for controlling insect pests, such as the Mediterranean fruit fly (Ceratitis capitata, Wiedemann). The effectiveness of the SIT depends on the ability of the sterile males to mate and their capacity to induce sterility in wild females. This study evaluated how the irradiation age affects their sexual performance, measured by the outcome of female remating events. Males of the GSS VIENNA 8D53− were irradiated at eleven different ages, from 72 h before emergence (pupal stage) to 72 h after emergence (adult stage) and mated with wild females. These females were subsequently allowed to mate with fertile males from the fluorescent TSS VIENNA 8 1260. The presence of fluorescent offspring was used as indicator of second-male paternity. Results showed that males irradiated at post-emergence ages produced the lowest egg-to-pupae conversion rate, indicating a greater ability to prevent females from producing offspring after remating with a fertile male. In contrast, males irradiated at pre-emergence ages were associated with higher numbers of fluorescent offspring. Although no significant differences were found in mating competitiveness (RSI), the outcome of the remating showed differences in the effectiveness of initial matings. These findings highlight the importance of considering the age of flies at time of irradiation in mass-rearing protocols to enhance the efficacy of SIT programs targeting C. capitata and suggest that irradiating males later in their life cycle, such as adult stages or in pupae close to adult emergence, limit offspring if females remate with fertile males in the field.

Suitability of a chilled environmental box of the Precision X-RAD 320 cabinet style irradiator for the irradiation of mosquitoes and tsetse in the context of the sterile insect technique

35276
Hanano Yamada, Bénéwendé Aristide Kaboré, Samar Eisa, et al.,  Journal of Economic Entomology,  2025-11-03 11:17:02.
A cabinet-style small animal X-irradiator outfitted with an environmental chamber which can provide a consistent, chilled environment during irradiation was tested to sterilize the human and animal disease vectors Aedes aegypti Linnaeus (Diptera: Culicidae), Anopheles arabiensis Patton (Diptera: Culicidae), Glossina palpalis gambiensis Vanderplank (Diptera: Glossinidae) in the frame of the sterile insect technique (SIT). The environmental chamber enables the irradiation of immobilized, compacted adult insects avoiding mechanical damage incurred by movement and, thereby, maintaining better insect quality. For the species tested, there was no significant difference in dose response when irradiating late-stage pupae or adults, and chilling at 7 °C did not affect irradiation outcome in terms of sterility induced. The X-irradiator was shown to be effective and suitable for the sterilization of these important target species of the SIT and offers a practical means to sterilize insects at the adult stage which require chilling for immobilization.

Impact of long-term mass-rearing on the genetic structure of tsetse fly Glossina palpalis gambiensis colonies

35273
Kiswend-sida M. Dera, Soumaïla Pagabeleguem, Tito Tresor Melachio Tanekou, et al.,  Insect Science,  32. 2025-11-02 17:49:38.
Tsetse flies are the sole cyclic vectors of African trypanosomes, which cause human and animal African trypanosomiases in Africa. Tsetse fly control remains a promising option for disease management. The sterile insect technique (SIT) stands as an environmentally friendly tool to control tsetse populations. SIT requires the mass-rearing of competent sterile males to mate with wild females. However, long-term colonization might affect the genetic structure of the reared flies. This study investigated the genetic structure of four Glossina palpalis gambiensis colonies of different ages: two originating from Senegal (SEN and ICIRSEN) and two from Burkina Faso (CIR and IBD). Samples from these colonies were genotyped at ten microsatellite loci, followed by downstream population genetic analyses. The results show that the two colonies from Burkina Faso collected from close sites (∼20 km apart) over 45-year interval retained the same genetic background (FST_CIR∼IBD ≈ 0, P-value = 0.47). These flies were however, genetically different from those from the Senegal colonies (FST_CIR∼SEN ≈ 0.047; FST_IBD∼SEN ≈ 0.058, P-value = 10−4). Moreover, no significant difference was detected in the gene diversity of the CIR and IBD colonies, with HS values of 0.650 and 0.665, respectively. The inbreeding coefficient showed that all four colonies where under Hardy–Weinberg equilibrium, with FIS values of 0.026, 0.012, −0.064, and 0.001, for CIR, IBD, ICIRSEN, and SEN, respectively. Furthermore, no sign of a recent bottleneck was identified in tsetse samples from any of the four colonies. The results suggest that long-term mass-rearing of tsetse flies has no significant impact on their genetic background and diversity.

The nanosd integral gene drive enables population modification of the malaria vector Anopheles gambiae

35269
Pei-Shi Yen, Sebald A N R Verkuijl, Paolo Capriotti, et al.,  G3 Genes|Genomes|Genetics,  2025-11-02 17:38:52.
The modification of mosquito populations at scale through CRISPR-Cas9-mediated homing gene drives is a promising route for malaria vector control. Integral gene drives (IGDs) are designed to utilise the regulatory sequences of endogenous genes to reduce the size of the modification required for nuclease and effector expression. In this study, we describe the creation and characterisation of the nanosd IGD, which targets and is inserted into the nanos gene of the malaria vector Anopheles gambiae, and show that it achieves high rates of gene drive (98.4% in females, 99.5% in males). We find that homozygous nanosd females but not males show impaired fecundity and exhibit variable degrees of ovary underdevelopment. Transcriptomic analysis of ovaries points to decreased transcript levels of the nanos gene when harbouring Cas9 and changes to other fertility-related genes. As a minimal genetic modification, nanosd does not induce widespread transcriptomic perturbations that would affect vector competence, and we show that its susceptibility to Plasmodium spp. and O’nyong nyong virus infection remains similar to wild-type mosquitoes. Importantly, we find that nanosd propagates efficiently in caged mosquito populations and is maintained as a source of Cas9 after the emergence of drive-resistant alleles, whilst also mobilising a non-autonomous antiparasitic effector modification. The nanosd gene drive shows promise as a genetic tool for malaria vector control via population modification, and we outline steps towards its further optimisation.

SIT-ia: A Software-Hardware System to Improve Male Sorting Efficacy for the Sterile Insect Technique

35267
de la Vega, G., Smith, L., Soria-Mercier, L., et al.,  Insects,  16. 2025-11-02 17:34:18.
This research addresses a challenge in using the Sterile Insect Technique (SIT), an eco-friendly pest control method. For SIT to work, only sterile male insects can be released, but sorting males from females by hand is slow and laborious. The study introduces a new automated system called SIT-ia that uses artificial intelligence (AI) to quickly and accurately tell male and female flies apart. When tested on the spotted-wing drosophila (Drosophila suzukii), the system was 98.6% accurate. A key benefit is its speed: SIT-ia can sort 1000 flies in about 70 min, which is 40 min faster than human experts. This innovation makes sex-sorting a more efficient and practical process, needed for managing pest insects in a sustainable way. Invasive insects can cause significant economic impacts to agriculture worldwide and impact human health. Traditional pest management methods that include chemical insecticides have raised increasing environmental and health concerns, prompting the need for sustainable alternatives. The Sterile Insect Technique (SIT), which consists of releasing sterile males of a target pest to mate with wild females, is held as a promising solution. However, the success of SIT relies on the release of sterile males. The efficient separation of sexes prior to sterilization and release is necessary. This study presents SIT-ia, a software–hardware system that utilizes artificial intelligence (AI) and computer vision to automate the sex-sorting process. We showcase its use with the fruit fly pest D. suzukii. The system was able to identify males from females with a 98.6% accuracy, sorting 1000 sterile flies in ~70 min, which is nearly half the time involved in manual sorting by experts (i.e., ~112 min). This simple device can easily be adopted in SIT production protocols, improving the feasibility and efficacy of improved pest management practices.

Highlight: Self-limiting gene drive suppresses malaria mosquitoes

35263
Gorm Palmgren,  CRISPR Medicine News,  2025-11-02 17:22:29.
Malaria claimed over 600,000 lives in 2022, with Anopheles gambiae serving as one of the most efficient vectors in sub-Saharan Africa, where approximately 96% of malaria deaths occur. The emergence of insecticide resistance threatens progress in disease control, prompting the development of genetic strategies to address it. CRISPR-homing gene drives have emerged as the most studied self-sustaining approaches, whilst various self-limiting methods that require repeated releases continue to be explored. The research team developed a system, termed Male-Drive Female-Sterile (MDFS), that exploits CRISPR-Cas9 to simultaneously perform two distinct functions (see Figure 1). The genetic construct contains an eCFP fluorescent marker, a Cas9 endonuclease under the control of the germline vasa2 promoter, and a guide RNA targeting the female-specific exon 5 of the doublesex gene. The construct was integrated into the doublesex locus at the intron 4–exon 5 boundary using recombinase-mediated cassette exchange.

A male-drive female-sterile system for the self-limited control of the malaria mosquito Anopheles gambiae

35261
Strampelli, A., Willis, K., Gulliford, H.R. et al.,  Nature Communications,  16. 2025-10-28 08:43:17.
Despite great leaps forward in preventing and treating malaria, several challenges, including insecticide resistance, have hindered progress in fighting the disease. Thus, there is a pressing need for new tools to control malaria, including the use of genetically modified mosquitoes (GMMs) in the field. Various genetic strategies for vector control are currently explored, ranging from self-sustaining GMMs with unrestricted geographic and temporal spread to self-limiting alternatives. Here, we describe a self-limiting gene drive strategy called Male Drive Female Sterile (MDFS) targeting Anopheles gambiae, a major malaria vector. The MDFS genetic construct causes dominant sterility in females, while transgenic males remain fertile, allowing them to transmit the female sterility trait at super-Mendelian rates. Laboratory studies show that repeated releases of MDFS can lead to elimination of caged mosquito populations. Based on these findings, modelling suggests MDFS could be a highly effective and self-limiting strategy for suppressing wild malaria mosquito populations.

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