Keywords: Genomics
Precision pest management: Genome editing tools, specifically CRISPR/Cas9 and future prospects
35424Ankush Saini, Neha Sharma, Nidhi Sharma, et al., Pesticide Biochemistry and Physiology, 218. 2026-02-03 15:42:17.
The growing resistance to synthetic insecticides and Bt toxins, alongside persistent crop losses despite heavy pesticide application, highlights the urgent need for safer, sustainable and efficient pest management strategies. This review presents genome editing as a precise and versatile approach to reduce pest impact by altering fertility, feeding patterns or vulnerability, while protecting beneficial organisms. Among the genome editing tools, CRISPR/Cas9 (Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR-associated protein 9) is one of the most promising genome editing techniques in insects. It facilitates targeted functional studies, integration with RNAi and dual-expression systems and gene drive applications. Deployment is envisioned in two phases, initial laboratory modification followed by regulated field release, with a strong emphasis on biosafety through terminator genes, marked individuals for gene flow monitoring, optimized dosages, stringent screening and long-term ecological surveillance, along with transparency and adherence to international safety protocols. Significant challenges encompass delivery efficiency, identification of edits, off-target mutations, dose-related efficacy and sterility, unstable transmission and resistance development. Innovations such as base and prime editing minimize unintended mutations by circumventing double-stranded breaks (DSBs), while paratransgenic strategies targeting gut symbionts offer supplementary avenues; plant-mediated insect gene editing emerges as a promising frontier. Overall, carefully regulated trials aligned with policy frameworks and stakeholder involvement are vital to assess effectiveness in natural environments and achieve targeted, dependable and ecologically responsible pest control.
The Evolutionary Genomics of Meiotic Drive
35407Daven C Presgraves, R Kelly Dawe, Kelly A Dyer, et al., Molecular Biology and Evolution, 2026-01-23 16:40:29.
Meiotic drivers are selfish genetic elements that gain transmission advantages by distorting equal, Mendelian segregation. For decades, biologists have considered meiotic drivers as interesting, albeit esoteric, case studies. It is now clear, however, that meiotic drive is more common and phylogenetically widespread than previously supposed. Indeed, intensive study of a few well-known cases has begun to reveal the evolutionary genomic consequences of meiotic drive. We argue here that many features of genome evolution, content, and organization that are seemingly inexplicable by organismal adaptation or nearly neutral processes are instead best accounted for by recurrent histories of meiotic drive. We review how meiotic drive can affect the evolution of sequences, gene copy numbers, genes with functions in meiosis and gametogenesis, signatures of “selection”, chromosome rearrangements, and karyotype evolution. We also explore the interactions of meiotic drive elements with other classes of selfish genetic elements, including satellite DNAs, transposable elements, and with the endogenous host genes involved in drive suppression. Finally, we argue that some aspects of drive-mediated genome evolution are now sufficiently well established that we might reverse the direction of discovery— rather than ask how drive affects genome evolution, we can use genome data to discover new putative drive elements.
Behavior modification in fruit flies through male annihilation technique: field applications, olfactory mechanisms, and future directions
35329Liu, Wei; Zhang, Sijia; Wang, Guirong, Entomologia Generalis, 45:1565 - 1576. 2026-01-06 14:51:47.
The male annihilation technique (MAT), as a method of insect behavior manipulation, is an environmentally friendly approach that has been successfully applied in over 150 fruit fly eradication programs worldwide. Despite their effectiveness in integrated pest management programs, concerns have long persisted about the safety of the primarily used male lures – particularly regarding the potential toxicity of methyl eugenol (ME). In this review, we propose a novel attractant screening and validation system for the future improvement of male lures, based on recent advancements in functional genomics and genetic manipulation technologies achieved in tephritid fruit flies. This system is built upon our knowledge of tephritid fruit flies’ core olfactory signal transduction pathway (“Male lures → Odorant receptors → Odorant receptor neurons → Glomerulus”). The working pipeline is centered around a transgenic Bactrocera strain with labeled male lure-responsive olfactory receptor neurons (ORNs) as the key targets. Electrophysiological responses and calcium activity serve as the readouts, while the decision criteria focus on increased intensity, stability, and specificity of neural activation induced by candidate compounds. This pipeline, compared to traditional behavior-first methods, enables the efficient screening of computationally identified candidate compounds and provides a foundation for evaluating their field stability and safety. More importantly, it represents a shift from empirical, field-based optimization to a molecularly guided, receptor-based design framework, advancing the development of enhanced male lure solutions for future applications in insect behavior manipulation.
Engineering gene drive docking sites in a haplolethal locus in Anopheles gambiae
35231Smidler, A.L., Marrogi, E.A., Scott, S. et al., Scientific Reports, 15. 2025-10-09 10:19:39.
Gene drives are selfish genetic elements which promise to be powerful tools in the fight against vector-borne diseases such as malaria. We previously proposed population replacement gene drives designed to better withstand the evolution of resistance by homing through haplolethal loci. Because most mutations in the wild-type allele that would otherwise confer resistance are lethal, only successful drive homing and functional r1 alleles permits the cell to survive. Here we outline the development and characterization of two ΦC31-Recombination mediated cassette exchange gene drive docking lines with these features in Anopheles gambiae, a first step towards construction of robust gene drives in this important malaria vector. We outline adaption of the technique HACK (Homology Assisted CRISPR knockin) to knock-in two docking site sequences into a paired putative haplolethal-haplosufficient (Ribosome–Proteasome) locus, and confirm that these docking lines permit insertion of drive-relevant transgenes. We report the first anopheline proteasome knockouts, and identify ribosome mutants in the process reveal a major lethality and infertility hurdle that such designs must overcome to develop robust drives in the future. Although we do not achieve drive, this work provides a new tool for constructing future evolution-robust drive systems and reveals critical challenges that must be overcome for development of future gene drives designed to target haplolethal loci in anophelines and, potentially, other metazoans.
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.
Lethal malaria parasite’s weaknesses revealed
34975Nature, 553. 2025-07-24 09:33:54.
A sweeping genomic analysis of the most deadly malaria parasite has revealed targets for more resilient drugs against the pathogen. The parasite Plasmodium falciparum has evolved resistance to every licensed drug. To aid the search for compounds that present higher barriers to resistance, a team led by Elizabeth Winzeler at the University of California, San Diego, exposed 262 strains of P. falciparum to a range of antimalarial agents. By analysing the genomes of strains that evolved resistance to the chemicals, the researchers identified the mutations that were most- and least-often linked to the parasite’s ability to survive an onslaught of antimalarial drugs. The team reasoned that genes with infrequent mutations would make good drug targets, because they seem less likely to adapt to new antiparasitic agents. Some of those genes code for enzymes, which can be targeted by drugs that are easier to administer than other types of therapy.
The B Chromosome of Pseudococcus viburni: A Selfish Chromosome that Exploits Whole-Genome Meiotic Drive
34939Isabelle M Vea, Andrés G de la Filia, Kamil S Jaron, Scott E J Barlow, Marion Herbette, Andrew J Mongue, Ross Nelson, Francisco J Ruiz-Ruano, Laura Ross, Genome Biology and Evolution, 17. 2025-06-24 08:56:02.
Meiosis is generally a fair process: each chromosome has a 50% chance of being included into each gamete. However, meiosis can become aberrant with some chromosomes having a higher chance of making it into gametes than others. Yet, why and how such systems evolve remains unclear. Here, we study the unusual reproductive genetics of mealybugs, where only maternal-origin chromosomes are included in gametes during male meiosis, while paternal chromosomes are eliminated. One species—Pseudococcus viburni—has a segregating B chromosome that drives by escaping paternal genome elimination. We present whole genome and gene expression data from lines with and without B chromosomes. We identify B-linked sequences including 204 protein-coding genes and a satellite repeat that makes up a significant proportion of the chromosome. The few paralogs between the B and the core genome are distributed throughout the genome, arguing against a simple, or at least recent, chromosomal duplication of one of the autosomes to create the B. We do, however, find one 373 kb region containing 146 genes that appears to be a recent translocation. Finally, we show that while many B-linked genes are expressed during meiosis, most of these are encoded on the recently translocated region. Only a small number of B-exclusive genes are expressed during meiosis. Of these, only one was overexpressed during male meiosis, which is when the drive occurs: an acetyltransferase involved in H3K56Ac, which has a putative role in meiosis and is, therefore, a promising candidate for further studies.
An innovation in host responses to escalating genomic conflicts
34753Martí, Emiliano et al., Trends in Genetics, 2025-04-07 12:54:24.
Conflicts between selfish elements and their hosts can trigger rapid structural and regulatory changes in genomes. Chen et al. discovered a novel species-specific innovation in response to a meiotic driver in Drosophila melanogaster. Their discovery highlights a new dimension in adaptive responses to selfish elements, with broad evolutionary consequences.
Identification of novel genes responsible for a pollen killer present in local natural populations of Arabidopsis thaliana
34259Ricou, A., Simon, M., Duflos, R., et al, PLOS Genetics, 21. 2025-01-14 09:53:12.
Gamete killers are genetic loci that distort segregation in the progeny of hybrids because the killer allele promotes the elimination of the gametes that carry the sensitive allele. They are widely distributed in eukaryotes and are important for understanding genome evolution and speciation. We had previously identified a pollen killer in hybrids between two distant natural accessions of Arabidopsis thaliana. This pollen killer involves three genetically linked genes, and we previously reported the identification of the gene encoding the antidote that protects pollen grains from the killer activity. In this study, we identified the two other genes of the pollen killer by using CRISPR-Cas9 induced mutants. These two genes are necessary for the killer activity that we demonstrated to be specific to pollen. The cellular localization of the pollen killer encoded proteins suggests that the pollen killer activity involves the mitochondria. Sequence analyses reveal predicted domains from the same families in the killer proteins. In addition, the C-terminal half of one of the killer proteins is identical to the antidote, and one amino acid, crucial for the antidote activity, is also essential for the killer function. Investigating more than 700 worldwide accessions of A. thaliana, we confirmed that the locus is subject to important structural rearrangements and copy number variation. By exploiting available de novo genomic sequences, we propose a scenario for the emergence of this pollen killer in A. thaliana. Furthermore, we report the co-occurrence and behavior of killer and sensitive genotypes in several local populations, a prerequisite for studying gamete killer evolution in the wild. This highlights the potential of the Arabidopsis model not only for functional studies of gamete killers but also for investigating their evolutionary trajectories at complementary geographical scales.
A meiotic driver hijacks an epigenetic reader to disrupt mitosis in noncarrier offspring
33620Yu Hua, Jianxiu Zhang, et al., PNAS, 121. 2024-11-12 14:39:25.
Killer meiotic drivers (KMDs) are selfish genetic elements that distort Mendelian inheritance by selectively killing meiotic products lacking the KMD element, thereby promoting their own propagation. Although KMDs have been found in diverse eukaryotes, only a limited number of them have been characterized at the molecular level, and their killing mechanisms remain largely unknown. In this study, we identify that a gene previously deemed essential for cell survival in the fission yeast Schizosaccharomyces pombe is a single-gene KMD. This gene, tdk1, kills nearly all tdk1Δ progeny in a tdk1+ × tdk1Δ cross. By analyzing polymorphisms of tdk1 among natural strains, we identify a resistant haplotype, HT3. This haplotype lacks killing ability yet confers resistance to killing by the wild-type tdk1. Proximity labeling experiments reveal an interaction between Tdk1, the protein product of tdk1, and the epigenetic reader Bdf1. Interestingly, the nonkilling Tdk1-HT3 variant does not interact with Bdf1. Cryoelectron microscopy further elucidated the binding interface between Tdk1 and Bdf1, pinpointing mutations within Tdk1-HT3 that disrupt this interface. During sexual reproduction, Tdk1 forms stable Bdf1-binding nuclear foci in all spores after meiosis. These foci persist in germinated tdk1Δ progeny and impede chromosome segregation during mitosis by generating aberrant chromosomal adhesions. This study identifies a KMD that masquerades as an essential gene and reveals the molecular mechanism by which this KMD hijacks cellular machinery to execute killing. Additionally, we unveil that losing the hijacking ability is an evolutionary path for this single-gene KMD to evolve into a nonkilling resistant haplotype.
Supergenes as drivers of ant evolution
27997M. Chapuisat, Myrmecological News, 33:1-18. 2023-09-30 08:25:16.
Ants show striking diversity in social organization, raising major questions on the proximate and ultimate causes of such variation. The shift from one-queen (= monogyne) societies to multi-queen (= polygyne) societies has long been viewed as a phenotypically plastic response to ecological and social conditions. In contrast to this view, in five independent ant lineages, alternative forms of colony social organization are controlled by supergenes. Supergenes are large groups of linked genes determining compound adaptive phenotypes, like colour morphs, ecotypes, or social forms. In the best-studied socially polymorphic ant species, Solenopsis invicta and Formica selysi, a supergene variant (= haplotype) is exclusively found in multi-queen colonies and does not recombine with the alternative haplotype. How did such supergenes spread? Supergenes might be favoured by natural selection because they link co-adapted alleles that are beneficial in one social form. The absence of recombination ensures that these alleles are transmitted together and prevents maladaptive combinations between alleles. However, supergenes can also spread selfishly, by distorting Mendelian transmission in their favour. Non-recombining regions are indeed prone to harbour selfish genetic elements, which are typically formed by tight linkage of a killer gene, or toxin, and a rescue gene, or antidote. Strikingly, the social supergene haplotypes associated with multi-queen colonies of ants selfishly favour their own transmission by causing gene drive through distinct mechanisms. In S. invicta, the “polygyne” haplotype causes a green-beard effect: Workers that carry this haplotype kill queens that lack it. In F. selysi, the “polygyne” haplotype is a maternal-effect killer: Offspring of mothers that carry this selfish haplotype fail to hatch when they do not inherit a copy of the haplotype. Overall, the ants’ social supergenes induce unexpected combinations of adaptive and detrimental effects across levels of biological organization. On the one hand, they coordinate individual and colony-level traits, such as queen number, mating system, and dispersal. On the other hand, supergenes cause selfish gene drive and lethal effects due to accumulation of deleterious mutations. The evolutionary dynamics of these large groups of linked genes is therefore particularly complex, and explaining their long-term maintenance is challenging. I argue that social supergenes can be drivers of ant evolution because they spread selfishly and show lethal effects. Therefore, an understanding of the unusual properties of the underlying genetic system is needed to explain variation in colony queen number.
How genomics can help biodiversity conservation
24754K. Theissinger, C. Fernandes, G. Formenti, I. Bista, P. R. Berg, C. Bleidorn, A. Bombarely, A. Crottini, G. R. Gallo, J. A. Godoy, S. Jentoft, J. Malukiewicz, A. Mouton, R. A. Oomen, S. Paez, P. J. Palsbøll, C. Pampoulie, M. J. Ruiz-López, S. Secomandi, H, Trends in Genetics, 2023-02-16 19:11:36.
Genomics provides effective tools to characterize biodiversity, but the full implementation of genomic techniques in practical conservation is still limited. We review some of the main approaches in biodiversity genomics available to conservationists and genomicists.High-quality, long-read sequencing and bioinformatic technologies facilitate genome sequencing and assembly for any species. We summarize how reference genomes, in conjunction with population genomic data, can contribute to biodiversity monitoring, conservation, and restoration efforts.Over the past decade, many initiatives to generate reference genomes spanning the tree of life have emerged worldwide. We call for increased integration of reference genomes and population genomics data into interdisciplinary conservation efforts to fully unlock the potential of genomics in safeguarding global biodiversity.
Cryptic recessive lethality of a supergene controlling social organization in ants
24183P. Blacher, O. De Gasperin, G. Grasso, S. Sarton-Lohéac, R. Allemann and M. Chapuisat, Molecular Ecology, 2022-12-11 11:15:44.
Supergenes are clusters of linked loci that control complex phenotypes, such as alternate forms of social organization in ants. Explaining the long-term maintenance of supergenes is challenging, particularly when the derived haplotype lacks homozygous lethality and causes gene drive. In the Alpine silver ant, Formica selysi, a large and ancient social supergene with two haplotypes, M and P, controls colony social organization. Single-queen colonies only contain MM females, while multi-queen colonies contain MP and PP females. The derived P haplotype, found only in multi-queen colonies, selfishly enhances its transmission through maternal effect killing, which could have led to its fixation. A population genetic model showed that a stable social polymorphism can only be maintained under a narrow set of conditions, which includes partial assortative mating by social form (which is known to occur in the wild), and low fitness of PP queens. With a combination of field and laboratory experiments, we show that the P haplotype has deleterious effects on female fitness. The survival rate of PP queens and workers was around half the one of other genotypes. Moreover, P-carrying queens had lower fertility and fecundity compared to other queens. We discuss how cryptic lethal effects of the P haplotype help stabilize this ancient polymorphism.
“Selfish Genetic Elements” – Supergene Wreaks Havoc in a Genome
23302University of Rochester, SciTechDaily, 2022-07-25 07:37:40.
“Selfish genetic elements” litter the human genome. They do not seem to benefit their hosts but instead seek only to propagate themselves. These selfish genetic elements can wreak havoc. For example, they can distort sex ratios, impair fertility, cause harmful mutations, and even potentially cause population extinction. Biologists have for the first time used population genomics to shed light on the evolution and consequences of a selfish genetic element known as Segregation Distorter (SD). These researchers at the University of Rochester, include Amanda Larracuente, an associate professor of biology, and Daven Presgraves, a University Dean’s Professor of Biology. In a paper published recently in the journal eLife, the scientists report that SD has caused dramatic changes in chromosome organization and genetic diversity.
Iterative evolution of supergene-based social polymorphism in ants
22899T. Kay, Q. Helleu and L. Keller, Philos Trans R Soc Lond B Biol Sci, 377:20210196. 2022-06-13 06:17:44.
Species commonly exhibit alternative morphs, with individual fate being determined during development by either genetic factors, environmental cues or a combination thereof. Ants offer an interesting case study because many species are polymorphic in their social structure. Some colonies contain one queen while others contain many queens. This variation in queen number is generally associated with a suite of phenotypic and life-history traits, including mode of colony founding, queen lifespan, queen-worker dimorphism and colony size. The basis of this social polymorphism has been studied in five ant lineages, and remarkably social morph seems to be determined by a supergene in all cases. These 'social supergenes' tend to be large, having formed through serial inversions, and to comprise hundreds of linked genes. They have persisted over long evolutionary timescales, in multiple lineages following speciation events, and have spread between closely related species via introgression. Their evolutionary dynamics are unusually complex, combining recessive lethality, spatially variable selection, selfish genetic elements and non-random mating. Here, we synthesize the five cases of supergene-based social polymorphism in ants, highlighting interesting commonalities, idiosyncrasies and implications for the evolution of polymorphisms in general. This article is part of the theme issue 'Genomic architecture of supergenes: causes and evolutionary consequences'.
Unbalanced selection: the challenge of maintaining a social polymorphism when a supergene is selfish
22895A. G. Tafreshi, S. P. Otto and M. Chapuisat, Philos Trans R Soc Lond B Biol Sci, 377:20210197. 2022-06-13 06:11:36.
Supergenes often have multiple phenotypic effects, including unexpected detrimental ones, because recombination suppression maintains associations among co-adapted alleles but also allows the accumulation of recessive deleterious mutations and selfish genetic elements. Yet, supergenes often persist over long evolutionary periods. How are such polymorphisms maintained in the face of selection, drive and drift? We present a population genetic model that investigates the conditions necessary for a stable polymorphic equilibrium when one of the supergene haplotypes is a selfish genetic element. The model fits the characteristics of the Alpine silver ant, Formica selysi, in which a large supergene underlies colony social organization, and one haplotype distorts Mendelian transmission by killing progeny that did not inherit it. The model shows that such maternal-effect killing strongly limits the maintenance of social polymorphism. Under random mating, transmission ratio distortion prevents rare single-queen colonies from invading populations of multiple-queen colonies, regardless of the fitness of each genotype. A stable polymorphic equilibrium can, however, be reached when high rates of assortative mating are combined with large fitness differences among supergene genotypes. The model reveals that the persistence of the social polymorphism is non-trivial and expected to occur only under restrictive conditions that deserve further empirical investigation. This article is part of the theme issue 'Genomic architecture of supergenes: causes and evolutionary consequences'.
Supergene potential of a selfish centromere
22893F. Finseth, K. Brown, A. Demaree and L. Fishman, Philos Trans R Soc Lond B Biol Sci, 377:20210208. 2022-06-13 06:07:46.
Selfishly evolving centromeres bias their transmission by exploiting the asymmetry of female meiosis and preferentially segregating to the egg. Such female meiotic drive systems have the potential to be supergenes, with multiple linked loci contributing to drive costs or enhancement. Here, we explore the supergene potential of a selfish centromere (D) in Mimulus guttatus, which was discovered in the Iron Mountain (IM) Oregon population. In the nearby Cone Peak population, D is still a large, non-recombining and costly haplotype that recently swept, but shorter haplotypes and mutational variation suggest a distinct population history. We detected D in five additional populations spanning more than 200 km; together, these findings suggest that selfish centromere dynamics are widespread in M. guttatus. Transcriptome comparisons reveal elevated differences in expression between driving and non-driving haplotypes within, but not outside, the drive region, suggesting large-scale cis effects of D's spread on gene expression. We use the expression data to refine linked candidates that may interact with drive, including Nuclear Autoantigenic Sperm Protein (NASP(SIM3)), which chaperones the centromere-defining histone CenH3 known to modify Mimulus drive. Together, our results show that selfishly evolving centromeres may exhibit supergene behaviour and lay the foundation for future genetic dissection of drive and its costs. This article is part of the theme issue 'Genomic architecture of supergenes: causes and evolutionary consequences'.
Epistatic selection on a selfish Segregation Distorter supergene: drive, recombination, and genetic load
22103B. Navarro-Dominguez, C.-H. Chang, C. L. Brand, C. A. Muirhead, D. C. Presgraves and A. M. Larracuente, eLife, 11:e78981. 2022-04-29 09:52:33.
In this work, we investigate the evolution and genomic consequences of an autosomal, multilocus, male meiotic drive system, Segregation Distorter (SD) in the fruit fly, Drosophila melanogaster. In African populations, the predominant SD chromosome variant, SD-Mal, is characterized by two overlapping, paracentric inversions on chromosome arm 2R and nearly perfect (~100%) transmission. We study the SD-Mal system in detail, exploring its components, chromosomal structure, and evolutionary history. Our findings reveal a recent chromosome-scale selective sweep mediated by strong epistatic selection for haplotypes carrying Sd, the main driving allele, and one or more factors within the double inversion. While most SD-Mal chromosomes are homozygous lethal, SD-Mal haplotypes can recombine with other, complementing haplotypes via crossing over, and with wildtype chromosomes via gene conversion. SD-Mal chromosomes have nevertheless accumulated lethal mutations, excess non-synonymous mutations, and excess transposable element insertions. Therefore, SD-Mal haplotypes evolve as a small, semi-isolated subpopulation with a history of strong selection. These results may explain the evolutionary turnover of SD haplotypes in different populations around the world, and have implications for supergene evolution broadly.
Wolbachia endosymbionts in two Anopheles species indicates independent acquisitions and lack of prophage elements
21788S. Quek, L. Cerdeira, C. L. Jeffries, S. Tomlinson, T. Walker, G. L. Hughes and E. Heinz, Microbial Genomics, 8. 2022-04-21 06:52:58.
Wolbachia is a genus of obligate bacterial endosymbionts that infect a diverse range of arthropod species as well as filarial nematodes, with its single described species, Wolbachia pipientis, divided into several ‘supergroups’ based on multilocus sequence typing. Wolbachia strains in mosquitoes have been shown to inhibit the transmission of human pathogens, including Plasmodium malaria parasites and arboviruses. Despite their large host range, Wolbachia strains within the major malaria vectors of the Anopheles gambiae and Anopheles funestus complexes appear at low density, established solely on PCR-based methods. Questions have been raised as to whether this represents a true endosymbiotic relationship. However, recent definitive evidence for two distinct, high-density strains of supergroup B Wolbachia within Anopheles demeilloni and Anopheles moucheti has opened exciting possibilities to explore naturally occurring Wolbachia endosymbionts in Anopheles for biocontrol strategies to block Plasmodium transmission. Here, we utilize genomic analyses to demonstrate that both Wolbachia strains have retained all key metabolic and transport pathways despite their smaller genome size, with this reduction potentially attributable to degenerated prophage regions. Even with this reduction, we confirmed the presence of cytoplasmic incompatibility (CI) factor genes within both strains, with wAnD maintaining intact copies of these genes while the cifB gene was interrupted in wAnM, so functional analysis is required to determine whether wAnM can induce CI. Additionally, phy logenetic analysis indicates that these Wolbachia strains may have been introduced into these two Anopheles species via horizontal transmission events, rather than by ancestral acquisition and subsequent loss events in the Anopheles gambiae species complex. These are the first Wolbachia genomes, to our knowledge, that enable us to study the relationship between natural strain Plasmodium malaria parasites and their anopheline hosts.
New developments in the field of genomic technologies and their relevance to conservation management
19273G. Segelbacher, M. Bosse, P. Burger, P. Galbusera, J. A. Godoy, P. Helsen, C. Hvilsom, L. Iacolina, A. Kahric, C. Manfrin, M. Nonic, D. Thizy, I. Tsvetkov, N. Veličković, C. Vilà, S. M. Wisely and E. Buzan, Conservation Genetics, 2021-11-11 16:22:03.
Recent technological advances in the field of genomics offer conservation managers and practitioners new tools to explore for conservation applications. Many of these tools are well developed and used by other life science fields, while others are still in development. Considering these technological possibilities, choosing the right tool(s) from the toolbox is crucial and can pose a challenging task. With this in mind, we strive to inspire, inform and illuminate managers and practitioners on how conservation efforts can benefit from the current genomic and biotechnological revolution. With inspirational case studies we show how new technologies can help resolve some of the main conservation challenges, while also informing how implementable the different technologies are. We here focus specifically on small population management, highlight the potential for genetic rescue, and discuss the opportunities in the field of gene editing to help with adaptation to changing environments. In addition, we delineate potential applications of gene drives for controlling invasive species. We illuminate that the genomic toolbox offers added benefit to conservation efforts, but also comes with limitations for the use of these novel emerging techniques.
Positive selection and horizontal gene transfer in the genome of a male-killing Wolbachia
19006T. Hill, R. L. Unckless and J. I. Perlmutter, Molecular Biology and Evolution, 2021-10-18 15:21:59.
Wolbachia are a genus of widespread bacterial endosymbionts in which some strains can hijack or manipulate arthropod host reproduction. Male killing is one such manipulation in which these maternally transmitted bacteria benefit surviving daughters in part by removing competition with the sons for scarce resources. Despite previous findings of interesting genome features of microbial sex ratio distorters, the population genomics of male-killers remain largely uncharacterized. Here, we uncover several unique features of the genome and population genomics of four Arizonan populations of a male-killing Wolbachia strain, wInn, that infects mushroom-feeding Drosophila innubila. We first compared the wInn genome to other closely related Wolbachia genomes of Drosophila hosts in terms of genome content and confirm that the wInn genome is largely similar in overall gene content to the wMel strain infecting D. melanogaster. However, it also contains many unique genes and repetitive genetic elements that indicate lateral gene transfers between wInn and non-Drosophila eukaryotes. We also find that, in line with literature precedent, genes in the Wolbachia prophage and Octomom regions are under positive selection. Of all the genes under positive selection, many also show evidence of recent horizontal transfer among Wolbachia symbiont genomes. These dynamics of selection and horizontal gene transfer across the genomes of several Wolbachia strains and diverse host species may be important underlying factors in Wolbachia’s success as a male-killer of divergent host species.
The Promise of Genetics and Genomics for Improving Invasive Mammal Management on Islands
17936B. T. Burgess, R. L. Irvine, G. R. Howald and M. A. Russello, Frontiers in Ecology and Evolution, 9. 2021-08-03 13:21:15.
Invasive species are major contributors to global biodiversity decline. Invasive mammalian species (IMS), in particular, have profound negative effects in island systems that contain disproportionally high levels of species richness and endemism. The eradication and control of IMS have become important conservation tools for managing species invasions on islands, yet these management operations are often subject to failure due to knowledge gaps surrounding species- and system-specific characteristics, including invasion pathways and contemporary migration patterns. Here, we synthesize the literature on ways in which genetic and genomic tools have effectively informed IMS management on islands, specifically associated with the development and modification of biosecurity protocols, and the design and implementation of eradication and control programs. In spite of their demonstrated utility, we then explore the challenges that are preventing genetics and genomics from being implemented more frequently in IMS management operations from both academic and non-academic perspectives, and suggest possible solutions for breaking down these barriers. Finally, we discuss the potential application of genome editing to the future management of invasive species on islands, including the current state of the field and why islands may be effective targets for this emerging technology.
Improving mosquito control strategies with population genomics
18781T. L. Schmidt, N. M. Endersby-Harshman and A. A. Hoffmann, Trends in Parasitology, 37:907-921. 2021-05-29 12:41:38.
Mosquito control strategies increasingly apply knowledge from population genomics research. This review highlights recent applications to three research domains: mosquito invasions, insecticide resistance evolution, and rear and release programs. Current research trends follow developments in reference assemblies, either as improvements to existing assemblies (particularly Aedes) or assemblies for new taxa (particularly Anopheles). With improved assemblies, studies of invasive and rear and release target populations are better able to incorporate adaptive as well as demographic hypotheses. New reference assemblies are aiding comparisons of insecticide resistance across sister taxa while helping resolve taxon boundaries amidst frequent introgression. Anopheles gene drive deployments and improved Aedes genome assemblies should lead to a convergence in research aims for Anopheles and Aedes in the coming years.
Detailed genome map of malaria vector
16381The Hindu, Aspirant World, 2021-02-14 15:03:12.
In order to engineer advanced forms of defence against malaria transmission, including targeted CRISPR and gene drive–based strategies, scientists require intricate knowledge of the genomes of vector mosquitoes. CRISPR technology is a gene-editing tool which allows researchers to easily alter DNA sequences and modify gene function.They produced a new reference genome for the Asian malaria vector mosquito Anopheles stephensi.
Researchers Unveil Detailed Genome of Invasive Malaria Mosquito
16374M. Aguilera, UC San Diego News Center, 2021-02-11 20:37:12.
Mosquito-transmitted malaria remains the number one worldwide killer among vector-borne diseases, claiming more than 400,000 human lives in 2019. In order to engineer advanced forms of defense against malaria transmission, including targeted CRISPR and gene drive-based strategies, scientists require intricate knowledge of the genomes of vector mosquitoes. Mahul Chakraborty—a project scientist at the University of California, Irvine, working with colleagues at the Tata Institute for Genetics and Society (TIGS) at UC San Diego and India, and the Institute of Bioinformatics and Applied Biotechnology in Bangalore, India—has produced a groundbreaking new reference genome for the Asian malaria vector mosquito Anopheles stephensi. Full details of the genome, which the scientists say is now on par with the best animal genomes available to science (humans and fruit flies), are published in the journal BMC Biology.
Hidden genomic features of an invasive malaria vector, Anopheles stephensi, revealed by a chromosome-level genome assembly
16376M. Chakraborty, A. Ramaiah, A. Adolfi, P. Halas, B. Kaduskar, L. T. Ngo, S. Jayaprasad, K. Paul, S. Whadgar, S. Srinivasan, S. Subramani, E. Bier, A. A. James and J. J. Emerson, BMC Biology, 19:28. 2021-02-10 20:40:13.
The mosquito Anopheles stephensi is a vector of urban malaria in Asia that recently invaded Africa. Studying the genetic basis of vectorial capacity and engineering genetic interventions are both impeded by limitations of a vector’s genome assembly. The existing assemblies of An. stephensi are draft-quality and contain thousands of sequence gaps, potentially missing genetic elements important for its biology and evolution.
Self-Deleting Genes Project To Tackle Mosquito-Borne Diseases
15923D. Ozdemir, INTERESTING ENGINEERING, 2021-01-08 18:58:57.
Did you know that mosquitoes kill at least 725,000 persons every year? They truly are one of the world's deadliest animals which is the reason why scientists from all around are trying to find new ways of dealing with them. Controlling mosquito populations and preventing them from transmitting disease at times through genetic engineering is one way of doing that. Now, a new Texas A&M AgriLife Research project has plans of enabling "test runs" of the proposed changes in mosquitoes that are automatically deleted from their genetic code. Researchers have used genetic engineering in the past to modify mosquitoes in a way that they pass on infertility, don't grow wings, can't spread malaria, or have impaired smell. However, as New Atlas reports, this sort of modification can have harmful consequences that may be impossible to reverse when released into the wild.
Edit, undo: Temporary gene editing could help solve the mosquito problem
15900L. Dormehl, digitaltrends, 2020-12-31 14:22:29.
But if SyFy original movies have taught us anything, it’s that genetically tweaking organisms and then releasing them can… well, not go quite according to plan.With that in mind, a new Texas A&M AgriLife Research project seeks to test out genetic modifications of mosquitos that would delete themselves from the genetic code after a certain period. This means that “test runs” of genetic changes could be made, knowing that everything will reset to normal after a designated period like one year (which equates to around 20 generations of mosquito).
Self-deleting genes promise risk-free genetic engineering of mosquitoes
15852D. Quick, New Atlas, 2020-12-29 18:53:49.
A new project by Texas A&M AgriLife Research is looking to enable "test runs" of genetic changes to mosquitoes that are automatically deleted. Various angles of attack using genetic engineering to combat mosquitoes have been pursued in recent years, including modifying them so they pass on infertility, don't grow wings, can't spread malaria or have impaired smell. But making genetic modifications to an organism and then releasing them into the wild runs the risk of unintended and harmful consequences that may be difficult to reverse. That's where the new Texas A&M AgriLife Research project comes in. It is looking to enable "test runs" of genetic modifications that would then automatically be deleted from the mosquitoes' genetic code after a period of time.
Self-deleting genes to be tested as part of mosquito population control concept
15926B. Hays, UPI, 2020-12-28 18:59:14.
Scientists at Texas A&M have developed a new technique for altering the genes of mosquitoes -- the new technology will cause genetic changes to self-delete from the mosquitoes' genome. Thanks to the breakthrough, described Monday in the Philosophical Transactions of the Royal Society B, researchers can now test-run experimental gene edits without permanently altering a mosquito's genome."People are wary of transgenes spreading in the environment in an uncontrolled manner. We feel that ours is a strategy to potentially prevent that from happening," Zach Adelman, professor of entomology at the Texas A&M College of Agriculture, said in a news release. "The idea is, can we program a transgene to remove itself? Then, the gene won't persist in the environment."
$3.9M project on self-deleting genes takes aim at mosquito-borne diseases
15847O. Kuchment, AGRILIFE Today, 2020-12-28 18:52:03.
To control mosquito populations and prevent them from transmitting diseases such as malaria, many researchers are pursuing strategies in mosquito genetic engineering. A new Texas A&M AgriLife Research project aims to enable temporary “test runs” of proposed genetic changes in mosquitoes, after which the changes remove themselves from the mosquitoes’ genetic code. The project’s first results were published on Dec. 28 in Philosophical Transactions of the Royal Society B, titled “Making gene drive biodegradable.”
Self-deleting genes tested as part of the concept of mosquito population control
15844charlottelarson, NEWYORK NEWS TIMES, 2020-12-28 18:49:28.
Most genetic engineering strategies designed to control mosquito populations, and their ability to spread diseases such as malaria, require gene editing to be combined with gene drives. Gene drives allow altered DNA to spread rapidly throughout the population.
Making gene drive biodegradable
15687J. Zapletal, N. Najmitabrizi, M. Erraguntla, M. A. Lawley, K. M. Myles and Z. N. Adelman, Philosophical Transactions of the Royal Society B: Biological Sciences, 376:20190804. 2020-12-28 15:02:10.
Here, we consider the inclusion of self-elimination mechanisms into the design of homing-based gene drive transgenes. This approach not only caused the excision of the gene drive transgene, but also generates a transgene-free allele resistant to further action by the gene drive. Strikingly, our models suggest that this mechanism, acting at a modest rate (10%) as part of a single-component system, would be sufficient to cause the rapid reversion of even the most robust homing-based gene drive transgenes, without the need for further remediation.
Study Could Lead to Power Over Parasite
13633D. Shore, 2020-08-06 14:13:11.
Scientists have long had a name for a gruesome insect that feeds on live flesh of warm-blooded mammals: C. hominivorax, Latin for “man eater.” But now, they have the parasite’s number. In a paper published this week in the journal Communications Biology, researchers from across the United States and beyond describe the assembly and analysis of the New World screwworm’s genome — a map of the fly’s 534 million DNA base pairs.
Genomic analyses of a livestock pest, the New World screwworm, find potential targets for genetic control programs
13618M. J. Scott, J. B. Benoit, R. J. Davis, S. T. Bailey, V. Varga, E. O. Martinson, P. V. Hickner, Z. Syed, G. A. Cardoso, T. T. Torres, M. T. Weirauch, E. H. Scholl, A. M. Phillippy, A. Sagel, M. Vasquez, G. Quintero and S. R. Skoda, Nature Communications, 3:424. 2020-08-04 12:56:38.
We identify and analyze the expression of genes that are likely important for host-seeking behavior (chemosensory), development of larvae in open wounds in warm-blooded animals (heat shock protein, immune response) and for building transgenic strains for genetic control programs including gene drive (sex determination, germline). This study will underpin future experiments aimed at understanding the parasitic lifestyle of the screwworm fly and greatly facilitate future development of strains for efficient systems for genetic control of screwworm.
Maternal effect killing by a supergene controlling ant social organization
12741A. Avril, J. Purcell, S. Béniguel and M. Chapuisat, Proceedings of the National Academy of Sciences, 2020-07-07 13:29:50.
Supergenes are clusters of linked loci producing complex alternative phenotypes. In a series of experiments, we demonstrate that a supergene controlling ant social organization distorts Mendel’s laws to enhance its transmission to adult offspring. One supergene haplotype is specific to multiple-queen colonies. This haplotype kills half of the offspring from heterozygous mothers—all eggs that do not inherit the haplotype fail to hatch. Hence, the haplotype associated with multiple-queen colonies is a selfish genetic element favoring its transmission to the detriment of the alternate haplotype associated with single-queen colonies. Selfish gene drive by a large group of linked genes impacts the social organization of ant colonies, which illustrates the intricate multilevel effects of supergenes.Supergenes underlie striking polymorphisms in nature, yet the evolutionary mechanisms by which they arise and persist remain enigmatic. These clusters of linked loci can spread in populations because they captured coadapted alleles or by selfishly distorting the laws of Mendelian inheritance. Here, we show that the supergene haplotype associated with multiple-queen colonies in Alpine silver ants is a maternal effect killer. All eggs from heterozygous queens failed to hatch when they did not inherit this haplotype. Hence, the haplotype specific to multiple-queen colonies is a selfish genetic element that enhances its own transmission by causing developmental arrest of progeny that do not carry it. At the population level, such transmission ratio distortion favors the spread of multiple-queen colonies, to the detriment of the alternative haplotype associated with single-queen colonies. Hence, selfish gene drive by one haplotype will impact the evolutionary dynamics of alternative forms of colony social organization. This killer hidden in a social supergene shows that large nonrecombining genomic regions are prone to cause multifarious effects across levels of biological organization.
Selfish genes and sexual selection: the impact of genomic parasites on host reproduction
11970N. Wedell, Journal of Zoology, 311:1-12. 2020-04-08 18:18:42.
Selfish genetic elements (SGEs) such as replicating mobile elements, segregation distorters and maternally inherited endosymbionts, bias their transmission success relative to the rest of the genome to increase in representation in subsequent generations. As such, they generate conflict with the rest of the genome. Such intragenomic conflict is also a hallmark of sexually antagonistic (SA) alleles, which are shared genes between the sexes but that have opposing fitness effects when expressed in males and females. However, whilst both SGEs and SA alleles are recognized as common and potent sources of genomic conflict, the realization that SGEs can also generate sexually antagonistic selection and contribute to sexual conflict in addition to generate sexual selection is largely overlooked. Here, I show that SGEs frequently generate sex-specific selection and outline how SGEs that are associated with compromised male fertility can shape female mating patterns, play a key role in the dynamics of sex-determination systems and likely be an important source of sexually antagonistic genetic variation. Given the prevalence of SGEs, their contribution to sexual conflict is likely to be greatly overlooked.
A bigger toolbox: Biotechnology in biodiversity conservation
6012R. T. Corlett, Trends in Biotechnology, 35:55-65. 2017-01-13 20:08:47.
Conservation biology needs a bigger toolbox to meet unprecedented challenges. Genomics, fueled by declining sequencing costs, offers novel tools with increased precision for genetic questions previously answered with a few molecular markers, as well as completely new possibilities. Metabarcoding promises quicker, cheaper, and more accurate assessments of biodiversity in groups that are difficult to assess by traditional methods, while sequencing low-quality DNA extends the range of useable materials to include museum specimens, archeological remains, and environmental samples. Genomic and transcriptomic data can be used to assess the potential of populations to adapt to new challenges. In the near future, gene-editing tools may help endangered species cope with change, while gene drives control unwanted species and help wanted ones. De-extinction has become a serious prospect.
A transatlantic perspective on 20 emerging issues in biological engineering
4073Wintle, BCB, C. R.; Rhodes, C.; Molloy, J. C.; Millett, P.; Adam, L.; Breitling, R.; Carlson, R.; Casagrande, R.; Dando, M.; Doubleday, R.; Drexler, E.; Edwards, B.; Ellis, T.; Evans, N. G.; Hammond, R.; Haseloff, J.; Kahl, L.; Kuiken, T.; Lichman, B. R.; Matthewman, C. A.; Napier, J. A.; OhEigeartaigh, S. S.; Patron, N. J.; Perello, E.; Shapira, P.; Tait, J.; Takano, E.; Sutherland, W. J., eLife, 6:21. 2017-01-11 00:00:00.
Advances in biological engineering are likely to have substantial impacts on global society. To explore these potential impacts we ran a horizon scanning exercise to capture a range of perspectives on the opportunities and risks presented by biological engineering. We first identified 70 potential issues, and then used an iterative process to prioritise 20 issues that we considered to be emerging, to have potential global impact, and to be relatively unknown outside the field of biological engineering. The issues identified may be of interest to researchers, businesses and policy makers in sectors such as health, energy, agriculture and the environment.
The Trojan Female Technique for pest control: a candidate mitochondrial mutation confers low male fertility across diverse nuclear backgrounds in Drosophila melanogaster
13733D. K. Dowling, D. M. Tompkins and N. J. Gemmell, Evolutionary Applications, 8:8710880. 2015-07-15 19:28:56.
The Trojan Female Technique (TFT) was recently proposed as a prospective approach to biological pest control. However, applicability of the TFT relies on mitochondrial mutations whose male-sterilizing effects are general across nuclear genomic contexts. We test this assumption, expressing the candidate TFT-mutation bearing haplotype alongside a range of nuclear backgrounds and comparing its fertility in males, relative to that of control haplotypes
Rapid evolution of yeast centromeres in the absence of drive
4233Bensasson, DZ, M.; Burt, A.; Koufopanou, V., Genetics, 178:2161-2167. 2008-01-11 00:00:00.
To find the most rapidly evolving regions in the yeast genome we compared most of chromosome III from three closely related lineages of the wild yeast Saccharomyces paradoxits. Unexpectedly, the centromere appears to be the fastest-evolving part of the chromosome, evolving even faster than DNA sequences unlikely to be under selective constraint (i.e., synonymous sites after correcting for codon usage bias and remnant transposable elements). Centromeres on other chromosomes also show an elevated rate of nucleotide substitution. Rapid centromere evolution has also been reported for some plants and animals and has been attributed to selection for inclusion in the egg or the ovule at female meiosis. But Saccharomyces yeasts have symmetrical meioses with all four products surviving, thus providing no opportunity for meiotic drive. In addition, yeast centromeres show the high levels of polymorphism expected tinder a neutral model of molecular evolution. We suggest that yeast centromeres suffer an elevated rate of mutation relative to other chromosomal regions and they change through a process of "centromere drift," not drive.
Sterility introduced by release of genetically altered males to a domestic population of Aedes aegypti at the Kenya coast
25875P. T. McDonald, W. Hausermann and N. Lorimer, Am J Trop Med Hyg, 26:553-61. 1977-05-06 07:09:31.
The release of males heterozygous for one or two sex-linked translocations was effective in introducing a high level of sterility into a domestic population of Aedes aegypti at a Rabai village. The effect of the releases continued for several weeks after the release period. Male mosquitoes, Aedes aegypti, were released at the Kenya coast to test the effectiveness of laboratory engineered mosquitoes in introducing a genetic mechanism and the ability of the mechanism to establish itself under field conditions. A triplicate of Rabai villages was selected for the experiment. In the 1st village nottreatment was made. In the 2nd village the domestic water containers were cleaned twice a week to remove larvae and pupae. Translocation males were released in the 3rd village. A mixture of 2 types of males was introduced: the single heteroxygote male selected from 78 translocations induced by irradiation in the African strains, and the double heterozygote male. Genetic analysis of the content of release samples determined quality control of released males. Fertility was also determined with females of a strain collected at Chibarani before releases began. Hatchability of eggs in all villages was counted to assay sterility in all villages. Before the releases population fluctuations in the 3 villages were monitored for 20 weeks. The release mixture had a fertility of 37% and the single heterozygote of 50%. A daily survival rate of .63 was shown for the dusted release males. There was close agreement between the monitoring for sterility for both the egg collections and the oviposition of the LB catch females. The sterility introduced into the Chibarani population was extensive.
Genetic control of insect populations: I. Cage studies of chromosome replacement by compound autosomes in Drosophila melanogaste
6297M. Fitz-Earle, D. G. Holm and D. T. Suzuki, Genetics, 74:461-475. 1973-07-08 19:53:27.
A genetic method for insect control was evaluated using the test organism, Drosophila melanogaster. The technique involved the displacement under a system of continuous reproduction, of standard strains by those carrying compound autosomes. The eradication of the replacements could subsequently be achieved through the use of temperature-sensitive lethal mutations.—While certain compound autosome strains failed to displace standards in population cages, even at the initial release ratio of 25:1, others were highly successful. Indeed, for some strains when the ratio of compounds to standards was as low as 9:1, the population rapidly went to fixation in favor of the compound line.—Hatchability was found to be an insufficient index of fitness to estimate the initial ratios of compounds to standards that would guarantee fixation of the former. Differences in other fitness components, such as development time, were detected that could seriously modify displacement, especially with continuous overlapping generations. The importance of examining the fitness of various compound lines and selecting the most competitive in cages, prior to field tests, cannot be overemphasized.
Changing population structure through the use of compound chromosomes
6295D. Childress, Genetics, 72:183-186. 1972-09-08 19:50:49.
Theoretical calculations and population cage data are presented to illustrate the use of compound chromosomes to change the genetic structure of insect populations.
Chromosome rearrangements for the control of insect pests
6293G. G. Foster, M. J. Whitten, T. Prout and R. Gill, Science, 176:875-880. 1972-05-26 19:48:27.
Over several years some biologists have been interested in the possibilities of employing genetic techniques in the control of insect pests. One idea has been to introduce in the natural population genotypes which could subsequently facilitate control, or which might render the pest innocuous. An- other idea that followed from the success of the .'sterile male" technique was to release genotypes with chromosomal aberrations whose subsequent segregation would result in sterility effects damaging to the population. Whitten (I) suggested combining these two ideas in one operation: in its simplest form the desired genotype would be obtained by incorporating the required genes in a chromosomal translocation. This would then be released as a homozygote in excess of the intrinsic unstable equilibrium which would result from the semisterility of the translocation heterozygote. The translocation producing the desired genotype would then autonomously become fixed while the genotype at the same time would produce sterile progeny in the early stages of the process. Thus we have the concept of a genetic transporting mechanism and a desired genotype to be transported, with the additional benefit of a transport device that might itself have transient damaging effects.
Insect control by genetic manipulation of natural populations
6300M. J. Whitten, Science, 171:682. 1971-02-19 19:57:36.
The possible use of chromosome rearrangements is considered as a means for introducing genes into insect populations for their own control. The release of laboratory-constructed strains differing from the field population for a number of chromosome interchanges should create an unstable situation leading to the rapid replacement of the field population. This replacement should allow introduction of genes for insecticide susceptibility, cold sensitivity, or the like. The process would produce sterile hybrids while the genetic displacement occurs which itself will contribute to a reduction in pest numbers.
Possible use of translocations to fix desirable genes in insect populations.
4503Curtis, CF, Nature, 218:368-369. 1968-01-21 00:00:00.
Chromosome translocation heterozygotes (T/+) are usually semisterile, but translocation homozygotes (T/T) if viable are usually fully fertile. If such a viable translocation were produced in an insect pest, T/T insects could be reared in captivity and released into the wild, where matings with wild types (+/+) would produce T/+ progeny.
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