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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“Target species complex” concept: Strengthening environmental risk assessment of engineered gene drives

35531
J.B. Connolly, Y. Devos, D.C.M. Glandorf, and J. Romeis,  Proc. Natl. Acad. Sci.,  2026-03-30 19:11:30.
The recent opinion piece of Christophe Boëte critiqued the concept of the target species complex (TSC) in environmental risk assessment (ERA) of engineered gene drives (EGDs) (1). While constructive debate is essential, the piece misrepresents the purpose of TSC and conflates unrelated mechanisms, creating misconceptions that merit clarification. Malaria-transmitting mosquitoes often belong to species complexes, comprising vector and nonvector species, where hybridization can be detected in laboratory settings and occasionally in the field (2–4). Low-threshold EGDs are self-sustaining and nonlocalizing (5). Should such EGD be released in a species complex where target genomic sequences are conserved, in the event of interspecific mating in the field vertical gene drive transfer (VGDT) to nonvector species could occur, potentially harming biodiversity protection goals. Conversely, VGDT to vector species could advance health objectives (6).

CRISPR-Cas9 suppression gene drives for Nile tilapia control: prospects in sub-Saharan African freshwater ecosystems

35509
Bobo, E. D.,  All Life,  19. 2026-03-16 15:14:01.
CRISPR-based suppression gene drives represent a promising tool for managing invasive Nile tilapia (Oreochromis niloticus) populations in sub-Saharan Africa’s freshwater ecosystems. Introduced through aquaculture, Nile tilapia supports livelihoods but also causes severe biodiversity loss. This review explores the technical feasibility of CRISPR-Cas9 suppression gene drives, specifically homing and Driving-Y drive systems, as species-specific, potentially self-sustaining biocontrol strategies. The theoretical effectiveness of these gene drive systems in reducing invasive Nile tilapia and restoring ecological balance is discussed within a precautionary framework. This study addresses the urgent need to protect native tilapia species, which are listed as Critically Endangered, Endangered, and Vulnerable by the IUCN. Gene drives have the potential to reduce invasive populations and restore ecological balance. However, their effectiveness can be compromised by extensive hybridization with native Oreochromis species and resistance evolution in genetically diverse populations. Therefore, the ecological, ethical, and socioeconomic risks of gene drive systems were examined in the context of the Convention on Biological Diversity and Cartagena Protocol. Hence, integrating molecular innovations with strong policy frameworks, stakeholder engagement, and comprehensive risk assessment is essential. CRISPR-Cas9 suppression drives deployment requires careful evaluation across ecological, ethical, and governance contexts to safeguard native ichthyofauna.

Editorial Overview – Insect Genomics (2026): enhancing public health, food security, and biodiversity through genetic biocontrol.

35506
Yoosook Lee, Omar S. Akbari,  Current Opinion in Insect Science,  2026-03-13 09:43:24.
Genetic biocontrol is a form of biological control in which genetic variants or genetically modified forms of the target species act to reduce or eliminate the target species. In entomology, target species include agricultural pests and vector species that transmit pathogens to human, animal, or plant systems. Examples include the Anopheles mosquito gene drive system to reduce or replace malaria vectors in Africa, the use of Wolbachia symbiont induced cytoplasmic incompatibility in Culex mosquitoes to project Hawaiian native birds from avian malaria related deaths, and the use of CRISPR to generate sterile males at a scale useful for suppressing pests of fruit crops. The widespread availability of robust transgenic technologies combined with new RNA-guided DNA endonuclease-based genome manipulation technologies and platforms and advances in synthetic biology are fueling the development of genetic biocontrol technologies and systems for combating arthropods that contribute to food insecurity, pathogen- and parasite-transmission, and invasive arthropods that threaten biodiversity. Heretofore a niche area of genetic biocontrol now commands great interest and an ever-growing number of applications.

Regulatory Provisions for Post-Release Monitoring of Genetically Modified Organisms in Africa

35497
Julia Njagi, John Muriuki, Paul Mbugua, et al.,  Frontiers in Bioengineering and Biotechnology,  2026-03-10 09:22:44.
Genetically modified (GM) crops with improved traits such as resistance to biotic and abiotic stresses and enhanced nutritional profiles have been commercially cultivated for over three decades. Despite extensive safety data and long-term cultivation experience, concerns continue to be raised about the potential risks and benefits of genetically modified organisms (GMOs). This is particularly true for the African region, where only eight out of fifty-four countries have so far commercialized GMOs. Upon release into the environment, GM crops may interact with ecosystems in complex ways, possibly leading to unanticipated ecological effects. Consequently, post-release monitoring of GMOs is essential to identify early signs of adverse impacts, enabling timely responses such as adjustments in risk management strategies, mitigation measures, or re-evaluation of previous regulatory decisions. A supportive policy and regulatory environment are critical for facilitating the safe development, testing, and commercialization of GMOs. This study conducted a desktop review of post-release monitoring frameworks for GMOs in selected African countries, as well as interviews with key informants in countries that have commercialized at least one GMO product. The findings reveal that most sampled countries lack clearly defined environmental protection goals and specific provisions regarding the scope and duration of post-release monitoring of GMOs. Where the duration of monitoring is prescribed, it is a blanket cover for all GMOs regardless of their life cycles. Moreover, the responsibility for monitoring is often delegated entirely to the applicant, and where local institutions are involved, there is no clear coordination mechanism for data sharing. These findings underscore the need for case-by-case monitoring approaches, guided by clearly articulated national protection goals and clear roles and coordination among stakeholders to ensure the safe and responsible deployment of GMOs.

Modelling Aedes albopictus management, incorporating immigration and bi-directional Wolbachia interactions

35520
Ryan, M., Mendiolar, M., Pagendam, D. et al.,  J Pest Sci,  99. 2026-03-10 09:16:51.
Aedes albopictus mosquitoes are competent vectors for the spread of at least 24 different arboviruses, including dengue, Ross River, and Japanese encephalitis viruses. However, they remain less studied than their more urban cousins, Aedes aegypti. We model an incompatible insect technique (IIT) strategy for mosquito control, with bi-directional incompatibility between two strains of Wolbachia (wAlbA/wAlbB   ARwP) and age-based cytoplasmic incompatibility decay in a well-mixed population. We include mosquito immigration to explore potential reversibility, an important consideration in bi-directional IIT control programs. We also explore the establishment probability after female contamination of an artificially-infected Wolbachia mosquito strain, consider the suppression dynamics and probability of mosquito management success for different release strategies, and determine a corresponding cost proxy for release (numbers of mosquitoes released). We found an establishment probability threshold of 40% in the absence of mating preferences, though this threshold needs validation in future field and laboratory experiments. We found differences in suppression success between release cessation and 6 months later for different immigration rates. There are similar short-term costs with differences in medium- and longer-term costs between release strategies. Our model suggests bi-directional IIT control programs are reversible with low amounts of wild-type immigration. This work demonstrates opportunities to optimise the suppression of these medically important mosquitoes.

Mark–release–recapture study of irradiated male Aedes albopictus under stressful field conditions

35492
Qingdeng Feng, Ming Li, Jeremy Bouyer, et al.,  Pest Management Science,  2026-03-09 10:33:54.
The sterile insect technique (SIT) suppresses mosquito populations by releasing sterile males. Its success mainly depends on the performance of sterile males. Mark–Release–Recapture (MRR) experiments are used to evaluate male performance in the field, yet most previous experiments were conducted under mild conditions (e.g. 25–28 °C) in which mosquitoes could easily adapt. Male mosquito performance under stressful field conditions remains poorly understood. This study evaluated the field performance of irradiated Aedes albopictus males under high-temperature conditions (>30 °C in average) in southern China, Foshan City, located in a sub-tropical area. Two MRR experiments were conducted in a 5-ha village during July–August of 2023 and 2024. Lifespan and dispersal of postreleased males were examined using BG-Sentinel mosquito traps, human landing catches, and ovitraps. A total of 54 546 and 58 440 sterile males were released in 2023 and 2024, respectively, with recapture rates of 8.53% and 5.64%. The mean dispersal distances ranged from 58.88–77.19 m (2023) to 81.82–90.86 m (2024). Daily survival probabilities were 0.15–0.28 in 2023 and 0.45–0.62 in 2024, corresponding to average expected lifespans of 0.53–0.78 days and 1.26–2.13 days, respectively. Estimated wild male densities ranged from 302–986 males ha−1 in 2023 to 416–3785 males ha−1 in 2024. Stressful field conditions severely reduced sterile male survival and dispersal, highlighting the need to optimize release protocols in challenging climates. These findings provide critical baseline data for advancing Ae. albopictus SIT programmes in southern China. 

Advances in male sex separation for the support of mosquito control programs

35526
Duman-Scheel M,  Frontiers in Insect Science,  6. 2026-03-09 09:05:10.
Several mosquito control technologies, including the sterile insect technique (SIT), the incompatible insect technique (IIT), and a variety of genetic technologies are emerging as promising solutions for combatting insecticide resistance and the spread of vector-borne diseases. These approaches involve mass releases of male mosquitoes in an effort to suppress mosquito populations in an eco-friendly manner. At small scale, male mosquito selection can be achieved through the use of mechanical separation techniques, but such methods are not sufficient for scaled implementation of emerging mosquito population control technologies. This review discusses mechanical, genetic, and automated mosquito sex sorting techniques that have emerged to address the need for scaled male mosquito production, as well as the potential contributions of RNA interference (RNAi) to facilitate this process. One RNAi method utilizes the oral delivery of yeast expressing interfering RNA targeting genes required for female larval survival. The yeast, which can be incorporated into normal insect larval diets, enables male sex selection during larval rearing in mosquitoes and could easily be extended to other insects. RNAi-mediated sex-sorting technologies, in combination with mechanical, genetic, and automated sorting technologies, could facilitate the scaled production of adult males in support of global insect population suppression efforts.

Discovery of a Genetic Toxin-Antidote System in Vertebrates

35490
Duilio Mazzoni Zerbinato A Silva, Morgan Skinner, Takaya Totsuka, et al.,  bioRxiv,  2026-03-06 10:25:21.
Toxin-antidote (TA) systems are selfish genetic elements that bias their own inheritance by coupling a toxin that kills daughter cells or offspring with an antidote that specifically rescues those with the TA. TAs are a widespread phenomenon, observed in bacteria, fungi, plants, and invertebrate animals, but have not yet been described in vertebrates. Here we report the first known vertebrate TA system that sabotages mammalian embryogenesis. The HSR locus on mouse chromosome 1 is a selfish genetic element that biases its transmission through the female germline. When HSR heterozygous females are crossed with wild-type males, wild-type embryos show high mortality, leading to preferential survival of embryos with HSR. The mechanism underlying embryo killing was unknown. We find that HSR kills wild-type post implantation embryos by depositing a toxin (SP100) that induces significant DNA damage. Embryos with HSR also inherit the toxin but survive by expressing an antidote (SP110) that blocks the effects of the toxin. Our findings reveal a previously unrecognized genetic cheating strategy in vertebrates and demonstrate its impact on mammalian reproduction.

Optimal spatial release strategies for confined gene drives and Wolbachia

35488
Ziye Wang, Jackson Champer,  bioRxiv,  2026-03-06 10:19:13.
Gene drives are genetic elements that can rapidly spread through populations, offering potential solutions for controlling disease vectors and pests. In some scenarios, it is necessary to utilize drives that can be confined to only target populations. The success of these threshold-dependent gene drives, which require a minimum local frequency to establish, depends critically on the spatial strategy used for introduction. Here, we use a reaction-diffusion model to systematically identify optimal release patterns that maximize the per-capita efficiency for four distinct gene drive designs as well as use of Wolbachia bacteria, which spread similarly to frequency-dependent gene drives. We find that the most efficient release strategy is highly dynamic, transitioning from a broad "everywhere" release for short timeframes to a "multiple-ring" pattern for intermediate times, and finally to a focused "center" release for longer timeframes. These timeframes depend on the specific type of drive, with more powerful variants transitioning more quickly to center releases. Our results demonstrate that these optimized, variable release strategies can be substantially more effective than simple uniform releases. This study provides a quantitative framework for designing effective gene drive implementations, highlighting that a carefully planned spatial strategy is essential for maximizing impact, making optimal use of available resources.

Wolbachia wMel and wAlbB strains differentially impact the vector competence of Aedes aegypti with a Brazilian genetic background for DENV-1 virus

35484
Martins, C.B., David, M.R., Couto-Lima, D. et al.,  Parasites Vectors,  2026-03-05 08:32:23.
Aedes aegypti mosquitoes infected with the endosymbiotic bacterium Wolbachia pipientis have been released as a sustainable strategy to mitigate arbovirus transmission. Among the strains successfully deployed, wMel and wAlbB have shown promising blocking effects against dengue virus (DENV). However, the strength of viral inhibition depends on Wolbachia density within mosquito tissues, the genetic backgrounds of both host and virus, and the viral dose. In this study, we aimed to investigate the vector competence for DENV-1 of Ae. aegypti with Brazilian genetic background infected with wMel or wAlbB. A total of 493 wild and wMel- and wAlbB-infected mosquitoes were orally challenged with low (5 × 104 FFU/mL) and high (5 × 105) titers of DENV-1. Relative Wolbachia density was measured by quantitative polymerase chain reaction (qPCR), and viral infection in mosquito bodies and saliva was assessed by qPCR with reverse transcription (RT-qPCR). Transmission potential was tested through saliva microinjection into susceptible mosquitoes. The infection prevalence and viral loads in mosquito bodies were analyzed at 7, 14, and 21 days post infection (dpi).Both Ae. aegypti groups infected with wMel and wAlbB had reduced (albeit distinct) DENV-1 infection and transmission relative to wild type mosquitoes. wMel-infected mosquitoes exhibited less abundant bacteria in their bodies but a greater degree of DENV-1 inhibition compared with those carrying wAlbB, indicating that DENV-1 blocking is strain specific rather than Wolbachia density-driven. Moreover, we observed that Wolbachia had a protective effect on mosquitoes by decreasing the DENV-1 loads in their bodies, but with a constant presence of virus. Viral transmission rates in the saliva were similar among wild and wMel- and wAlbB-infected mosquitoes at 7 and 14 dpi but lower in wMel and wAlbB mosquitoes at 21 dpi. The similar DENV-1 loads in mosquito bodies over time (7, 14, and 21 dpi) infected with either the wMel or wAlbB strain, regardless of the viral titer of the infectious blood meal, suggest that Wolbachia may have a maximum pathogen-blocking capacity beyond which additional virus suppression cannot be achieved. The viral suppression only after 21 dpi in the saliva raises concerns and warrants further investigation, as females may transmit before Wolbachia blockage becomes effective. While wAlbB may exhibit comparable DENV-1 blocking to wMel, its enhanced thermal tolerance makes it epidemiologically relevant in tropical regions. Continuous monitoring of Wolbachia dynamics and DENV genomic variation in the field remains essential to evaluate long-term effectiveness and detect potential adaptive viral responses.

Comparison of single-cell sequencing technologies for allele-specific expression analysis in rabbit spermatids

35482
Elena Smertina, Madi Rutherford, Brendan Hosking, et al.,  Genomics,  2026-03-05 08:26:37.
Gene drives are transmission distorters that can transmit specific alleles to >90% of the progeny, e.g., the naturally occurring t-haplotype in mice. For invasive pest species, there is interest in co-opting naturally occurring gene drives. It is unknown whether similar natural gene drives exist in the European rabbit, one of the most detrimental pest species in Australia. Here, we analysed the allele-specific expression (ASE) in rabbit spermatids to identify candidate genes for future investigation in genetic biocontrol applications. We utilised short-read and long-read technologies and performed a comparative analysis. Illumina sequencing was deemed unsuitable, whereas both long-read sequencing platforms demonstrated a similar performance. The SPINK2 gene that plays an important role in fertility, consistently showed ASE towards one of the alleles in all samples. Furthermore, two kinases were found to display a bimodal allele expression. Future work is warranted to assess suitability of these genes for genetic biocontrol applications.

Present and Future of Mosquito-Borne Disease Control in Europe with a Specific Focus on the Mediterranean

35535
Cholvi, M., Moretti, R., Osório, H. C., et al.,  Insects,  17. 2026-02-27 19:18:24.
Mosquito-borne diseases are an emerging public health challenge in Europe, driven by the spread of invasive mosquito species capable of sustaining outbreaks of tropical arboviral diseases. Rising temperatures, shifting precipitation patterns, human-driven habitat changes, and prolonged transmission seasons have increased the risk of dengue, chikungunya, and West Nile virus outbreaks, among other vector-borne diseases. Effective control requires a multifaceted approach, combining traditional and novel methods with advanced surveillance technologies and community involvement. However, growing insecticide resistance and concerns about insecticide use highlight the need for more prudent management of current tools and the development of innovative alternatives. Genetic control strategies, including the Sterile Insect Technique (SIT), Wolbachia-based approaches, and genetically modified (GM) mosquitoes, offer promising solutions but still face scientific, regulatory, and societal challenges. This review explores the current landscape of mosquito-borne disease control in Mediterranean Europe, emphasizing key challenges and emerging solutions. An integrated approach that strengthens surveillance, promotes sustainable control methods, and incorporates novel biotechnological tools supported by smart technologies will be essential to reduce the future burden of mosquito-borne diseases in the region.

Potential benefits, opportunities, risks and challenges of population suppression gene drive mosquitoes for malaria control described in the scholarly literature: a rapid scoping review

35472
Fürer, C. L., Fischer, T. B., Suter, T., Winkler, M. S., and Knoblauch, A. M.,  Impact Assessment and Project Appraisal,  2026-02-27 18:07:52.
Gene drive mosquitoes represent a promising strategy to alter mosquito populations and reduce disease transmission. However, their use has generated considerable debate due to ecological, ethical, and societal concerns. This paper reviews risks, challenges, benefits, and opportunities of gene drive technology, focusing on environmental, social, economic, and health implications. A literature search of peer-reviewed articles published between January 2019 and September 2023 was conducted using PubMed, Cochrane, Embase (Elsevier), and Google Scholar. Eligible papers included keywords such as ‘gene drive’, ‘mosquitoes’, and ‘Anopheles’. Extracted statements were grouped as ‘risks/challenges’, ‘benefits/opportunities’, or ‘ambivalent’, and classified across five dimensions: environmental/entomological/ecological, social, economic, health, and technological. From 1304 papers identified, 53 were included, yielding 892 statements. Of these, 66.5% addressed ‘risks/challenges’, 26.3% ‘benefits/opportunities’, and 7.2% were ‘ambivalent’. Most statements were classified under the ‘environmental/entomological/ecological’ dimension (46.1%), followed by ‘social’ (24.6%), ‘health’ (18.5%), ‘GM technology’ (7.2%), and ‘economic’ (3.6%). Commonly cited ‘risks/challenges’ included potential off-target effects, fitness costs, and development of resistance. The breadth of identified considerations, alongside the predominantly risk-focused discourse, highlights the need for multidimensional assessments. Early evaluations should integrate biosafety assessments with inclusive frameworks such as Strategic Environmental Assessments (SEA) and Environmental, Social, and Health Impact Assessments (ESHIA) to support responsible deployment.

Locally Acquired Dengue in Townsville, Australia, 2024–2025: An Outbreak Report in a Non-Endemic Region with wMel Wolbachia-Infected Aedes aegypti

35533
Thompson, K., Lyons, S., Malone, K., Fryk, J., Pyke, A., & Murton, K.,  Tropical Medicine and Infectious Disease,  11. 2026-02-26 19:11:49.
During the 2024/2025 wet season, Townsville had its first sustained autochthonous outbreak of dengue disease caused by dengue virus type 2 (DENV-2), the second locally transmitted outbreak of dengue since 2014 following the introduction of wMel strain Wolbachia-infected mosquitoes, a control strategy for dengue virus (DENV) and other Aedes-transmitted arboviruses. In comparison to two recorded locally acquired cases of dengue in 2020, the 2024/2025 outbreak resulted in sixteen cases in two inner-city suburbs of Townsville during the wet season associated with higher-than-average rainfall. This second dengue outbreak since 2014 highlights that Townsville and other north Queensland communities where Wolbachia mosquito programs have been deployed remain vulnerable to DENV incursions and local disease outbreaks despite the apparent high coverage of Wolbachia-infected mosquitoes. Whilst these control strategies have likely contributed to a reduction in the number and frequency of autochthonous DENV outbreaks in north Queensland, ongoing maintenance and monitoring of Wolbachia-infected mosquito coverage is necessary, together with timely review and improvement in dengue awareness and prevention health promotion activities in the community.

Ecological analysis of mosquito larval communities in Burkina Faso to inform environmental monitoring of genetic control programs

35470
Toé, I., Kientega, M., Lingani, A.J. et al.,  Scientific Reports,  16. 2026-02-24 14:26:04.
In Burkina Faso, the development of the gene drive technology targeting Anopheles coluzzii raises important ecological questions about potential non-target effects. Understanding interactions in mosquitoes’ natural environments is crucial for developing effective post-release environmental safety monitoring. This study assesses the ecological exposure and potential risks to non-target organisms associated with An. coluzzii suppression. Using co-occurrence, niche overlap metrics, and characterisation of physicochemical parameters, we evaluated interspecific relationships among mosquitoes and macroinvertebrate taxa from larval habitats in Burkina Faso. Combined index revealed distinct ecological relationships, ranging from competitive or facilitative coexistence to spatial segregation driven by predation or behavioural avoidance. Based on these interactions, an exposure score was developed to quantify the potential susceptibility of non-target organisms to ecological changes following the removal of An. coluzzii. The results showed variable exposure among taxa, with An. gambiae s.s. having the highest score, followed by An. arabiensis and Culex spp. Predatory taxa such as Corixidae showed niche overlap but limited spatial co-occurrence, suggesting effective predation. The detection of hybrid forms (An. coluzzii x An. gambiae s.s.) further highlights the potential for gene flow. This study introduces a quantitative framework that combines ecological indices and exposure scores to predict potential risks to non-target organisms.

Stochastic dynamics at the back of a gene drive eradication wave

35468
Léna Kläy, Léo Girardin, Florence Débarre, Vincent Calvez,  Theoretical Population Biology,  168:44-64. 2026-02-24 14:22:40.
Gene drive alleles bias their own inheritance to offspring. They can fix in a wild-type population in spite of a fitness cost, and even lead to the eradication of the target population if the fitness cost is high. However, this outcome may be prevented or delayed if areas previously cleared by the drive are recolonised by wild-type individuals. Here, we investigate the conditions under which these stochastic wild-type recolonisation events are likely and when they are unlikely to occur in one spatial dimension. More precisely, we examine the conditions ensuring that the last individual carrying a wild-type allele is surrounded by a large enough number of drive homozygous individuals, resulting in a very low chance of wild-type recolonisation. To do so, we make a deterministic approximation of the distribution of drive alleles within the wave, and we split the distribution of wild-type alleles into a deterministic part and a stochastic part. Our analytical and numerical results suggest that the probability of wild-type recolonisation events increases with lower fitness of drive individuals and with smaller local carrying capacity. Numerical simulations show that these results extend to two spatial dimensions. The role of the migration rate however, is less clear but has a lower impact. We further demonstrate that, in the event of wild-type recolonisation, the probability of subsequent drive reinvasion decreases with smaller values of the intrinsic growth rate of the population. Overall, our study paves the way for further analysis of wild-type recolonisation at the back of eradication travelling waves.

A distorter–restorer system drives quantitative reproductive isolation in rice

35461
Zhang, Y., Yang, Y., Shi, C. et al.,  Nature Plants,  2026-02-24 10:08:29.
Hybrid sterility and segregation distortion are the major forms of postzygotic reproductive isolation in rice, yet the molecular basis of their quantitative variation remains unclear. Here we identify S44, a natural distorter–restorer system in Oryza longistaminata/Asian cultivated rice hybrids, comprising four tightly linked elements—Reproductive Isolation Distorter (RID), Reproductive Isolation Restorer (RIR), Reproductive Isolation Activator (RIA) and Reproductive Isolation Suppressor (RIS)—which collectively regulate hybrid male sterility and segregation distortion. The distorter RID triggers the elimination of O. sativa cultivar RD23 pollen, whereas the restorer RIR selectively safeguards O. longistaminata gametes, thereby preferentially transmitting its allele into the progeny. RIS and RIA fine-tune segregation distortion. We further demonstrate that the allelic conflicts at the S44 locus drive quantitative reproductive isolation between O. longistaminata and other rice lineages, and CRISPR-engineered RID knockout can universally overcome S44-mediated reproductive barriers in the AA genome, enabling revolutionary cross-species breeding. This distorter–restorer system provides a unique genetic module for deciphering speciation mechanisms and advancing crop breeding strategies.

Spatial confinement of gene drives: Assessing risk of failure using global sensitivity analysis

35459
Cole D. Butler, Alun L. Lloyd,  bioRxiv,  2026-02-19 09:59:30.
Gene drives allow pest populations to be genetically modified to reduce their harm on agriculture and human health. The genetic modification, or payload, spreads within a target population at rates exceeding normal Mendelian inheritance. While gene drives have demonstrated immense potential in laboratory populations, they present unique challenges. Foremost among these challenges is spatial confinement, or ensuring that the payload remains confined to target populations. However, there is an inherent tension between gene drive spread and spatial confinement: increasing the spreading efficiency of a gene drive increases the risk of escape, while engineering confinement mechanisms increases the risk of gene drive extinction. In this work, we explore spatial outcomes in gene drives designed for spatial confinement and the dependence of these outcomes on target organism dispersal and payload fitness cost. We use a stochastic spatial model to compute the probability of failure for each gene drive, and use techniques from global sensitivity analysis to quantify the contribution of dispersal and fitness cost to variance in gene drive performance. Our findings reveal how spatial outcomes are affected by key parameters, and how this sensitivity varies tremendously between different gene drives. These spatial properties can be used to classify gene drive behavior and are useful to determine suitability for a particular application.

Upper bound on the mutational burden imposed by a CRISPR-Cas9 gene-drive element

35463
Michael S Overton, Sean E Guy, Xingsen Chen, et al.,  G3 Genes|Genomes|Genetics,  2026-02-18 10:08:37.
Homing-based CRISPR-Cas9 gene drives (CCGDs) are powerful tools for genetic control of wild populations, with applications from disease eradication to species conservation. However, Cas9 alone and in a complex with guide RNA can cause double-stranded DNA breaks at off-target sites, which could increase the mutational load and lead to unintended loss-of-heterozygosity (LOH) events. These undesired effects raise potential concerns about the long-term evolutionary safety of CCGDs, but the magnitude of these effects is unknown. To measure how the presence of a CCGD or a Cas9 alone in the genome affects the rates of LOH events and de novo mutations, we carried out a mutation accumulation experiment in yeast Saccharomyces cerevisiae. We found no detectable effects on the genome-wide rates of mutations or LOH events. Our power calculations suggest that CCGD or Cas9 affect these rates by less than 30%, which is much less than natural variation for these traits in yeast. A more detailed examination shows that CCGD or Cas9 may alter the lengths and genomic distributions of LOH events, but the statistical support for these effects is weak. Thus, our results demonstrate that CCGDs impose at most a weak additional mutational burden in the yeast model. Although mutagenic effects of gene drives need to be further evaluated in other systems, our results add credence to the proposition that the evolutionary risks posed by well-designed gene drives may be acceptable.

Evaluation of local larval diets for mass rearing of Aedes aegypti to support sterile insect technique programs in Burkina Faso Get

35466
Bouraïma Vincent Séré, Simon P Sawadogo, Prisca S L Paré, et al.,  Journal of Medical Entomology,  63. 2026-02-16 14:16:30.
Aedes aegypti Linnaeus 1762 is the primary vector of several viruses that cause arboviral diseases. Control strategies, such as SIT, require large-scale mosquito (Diptera: Culicidae) production, which depends critically on larval nutrition. However, the high cost and limited availability of conventional feed components hinder SIT implementation, particularly in resource-limited settings. Faced with this situation, it is imperative to find locally produced food sources. Here, we assessed six locally derived diets for their suitability in mass rearing Aedes aegypti. The diets include: (B) African Clarias gariepinus Burchell 1822 (Siluriformes: Clariidae) dried without additives; (C) Cirina butyrospermi Vuillet 1911 (Lepidoptera: Saturniidae) dried without additives; (D) Glycine max (L.) Merr., 1917 without additives; (E) a 1:1 mixture of Clarias gariepinus and Cirina butyrospermi; (F) a 1:1 mixture of Clarias gariepinus and Glycine max; and a mixture of 50% Clarias gariepinus, (G) 25% Glycine max and 25% Cirina butyrospermi. (A) Commercial fish food formulation (TetraMin® Baby) served as the control. Diets C and D were associated with significantly delayed while diets C, D, and E yielded fewer adults than the control. In contrast, diets B and G provided the most favorable balance of development time, adult emergence, and survival, comparable to the control group. Diets D and F produced the lowest fecundity and hatch rates, whereas diet G generated large, fertile adults. Collectively, these findings indicate that diets B and G are suitable for mass rearing, with diet G emerging as a cost-effective alternative for SIT programs targeting Aedes aegypti in Burkina Faso.

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