Keywords: Genetics &

The origin of island populations of the African malaria mosquito, Anopheles coluzzii

M. Campos, M. Hanemaaijer, H. Gripkey, T. C. Collier, Y. S. Lee, A. J. Cornel, J. Pinto, D. Ayala, H. Rompao and G. C. Lanzaro,  Communications Biology,  4:9. 2021.
Anopheles coluzzii is a major malaria vector throughout its distribution in west-central Africa. Here we present a whole-genome study of 142 specimens from nine countries in continental Africa and three islands in the Gulf of Guinea. This sample set covers a large part of this ...
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Selfish chromosomal drive shapes recent centromeric histone evolution in monkeyflowers

F. R. Finseth, T. C. Nelson and L. Fishman,  PLOS Genetics,  17:e1009418. 2021.
Centromeres must mediate faithful chromosomal transmission during cell division and sexual reproduction, but both the DNA and protein components of centromeres diverge rapidly across species. The selfish centromere model argues that this paradoxical diversity results from a ...
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Sex Determination and Dosage Compensation: femaleless Is the Link in Anopheles Mosquitoes

M. Scott,  Current Biology,  31:R260-R263. 2021.
A new study finds that the femaleless gene is essential for sexual development and repression of X-chromosome dosage compensation in the malaria vector Anopheles gambiae. This could provide the basis for a new genetic approach to control this pest.
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Regulating the expression of gene drives is key to increasing their invasive potential and the mitigation of resistance

A. Hammond, X. Karlsson, I. Morianou, K. Kyrou, A. Beaghton, M. Gribble, N. Kranjc, R. Galizi, A. Burt, A. Crisanti and T. Nolan,  PLOS Genetics,  17:e1009321. 2021.
Here we show that restricting the cutting activity of the gene drive to the germline tissue is crucial to maintaining its potency and we illustrate how failure to restrict this activity can lead to the generation of mutations that can make mosquitoes resistant to the gene drive.
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Mosquito Sexual Selection and Reproductive Control Programs

L. J. Cator, C. A. S. Wyer and L. C. Harrington,  Trends in Parasitology,  2021.
Recent work has generated many key insights about specific aspects of mating behavior and physiology. Here, we synthesize these findings and classify swarming mosquito systems as polygynous. Male mating success is highly variable in swarms and evidence suggests that it is likely ...
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A CRISPR endonuclease gene drive reveals two distinct mechanisms of inheritance bias

S. A. N. Verkuijl, E. González, J. X. D. Ang, M. Li, N. P. Kandul, M. Anderson, O. S. Akbari, M. Bonsall and L. Alphey,  bioRxiv,  2020.12.15.421271. 2020.
In this study, we report the functioning of sds3, bgcn, and nup50 expressed Cas9 in an Aedes aegypti homing split drive system targeting the white gene. We report their inheritance biasing capability, propensity for maternal deposition, and zygotic/somatic expression. ...
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A Gene Drive Could Wipe Out Mosquitoes. But What If We Want To Turn It Off?

A. Winkler,  freethink,  2020.
Gene drives are powerful tools: they allow scientists to hack how animals pass down genes to their offspring. They could allow us to wipe out malaria-carrying mosquitoes, preserve endangered species, or fight off crop-eating pests. But once it's out in the wild, a gene drive ...
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Targeting female flight for genetic control of mosquitoes

D. Navarro-Payá, I. Flis, M. A. E. Anderson, P. Hawes, M. Li, O. S. Akbari, S. Basu and L. Alphey,  PLOS Neglected Tropical Diseases,  14:e0008876. 2020.
The yellow fever mosquito and the Southern house mosquito are important vectors of infectious diseases. Given their widespread presence across tropical and subtropical regions of the world and the increased risk of spread due to global warming there is a growing need for ...
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Gene drive blocks malaria transmission in mosquitoes

labonline,  labonline,  2020.
Employing a strategy known as ‘population modification’, which involves using a CRISPR-Cas9 gene drive system to introduce genes preventing parasite transmission into mosquito chromosomes, University of California (UC) researchers have made a major advance in the use of ...
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A gene-drive rescue system for the modification of malaria mosquito populations

A. Adolfi,  Nature Research Bioengineering Community,  2020.
Mosquito populations can now be reliably modified using 1) antimalarial molecules that block parasite development and 2) a CRISPR-based gene drive system that mediates their rapid spreading across the vector population.
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A test for meiotic drive in hybrids between Australian and Timor zebra finches

U. Knief, W. Forstmeier, Y. Pei, J. Wolf and B. Kempenaers,  Ecology and Evolution,  2020.
We did not find evidence for meiotic driver loci on specific chromosomes. However, we observed a weak overall transmission bias toward Timor alleles at centromeres in females (transmission probability of Australian alleles of 47%, nominal p = 6 ? 10?5). While this is in line ...
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UC researchers pioneer more effective method of blocking malaria transmission in mosquitoes

UCI,  UCI News,  2020.
University of California, Irvine postdoctoral researcher Adriana Adolfi, in collaboration with colleagues at UCI, UC Berkeley and UC San Diego, followed up on the group’s pioneering effort to develop CRISPR-based gene drive systems for making mosquito vectors resistant to ...
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Efficient population modification gene-drive rescue system in the malaria mosquito Anopheles stephensi

A. Adolfi, V. M. Gantz, N. Jasinskiene, H.-F. Lee, K. Hwang, G. Terradas, E. A. Bulger, A. Ramaiah, J. B. Bennett, J. J. Emerson, J. M. Marshall, E. Bier and A. A. James,  Nature Communications,  11:5553. 2020.
Here, we develop a recoded gene-drive rescue system for population modification of the malaria vector, Anopheles stephensi, that relieves the load in females caused by integration of the drive into the kynurenine hydroxylase gene by rescuing its function. Non-functional resistant ...
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Cellular mechanisms regulating synthetic sex ratio distortion in the Anopheles gambiae germline

R. E. Haghighat-Khah, A. Sharma, M. R. Wunderlich, G. Morselli, L. A. Marston, C. Bamikole, A. Hall, N. Kranjc, C. Taxiarchi, I. Sharakhov and R. Galizi,  Pathogens and Global Health,  114:370-378. 2020.
Meiotic cleavage of rDNA repeats, located in the sex chromosomes of A. gambiae SD males, affects the competitiveness of mature sperm to fertilize the female oocyte.
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Viral gene drive in herpesviruses

M. Walter and E. Verdin,  Nature Communications,  11:4884. 2020.
Here, we report on a gene drive system that allows the spread of an engineered trait in populations of DNA viruses and, in particular, herpesviruses.
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Underlying beliefs linked to public opinion about gene drive and pest-specific toxin for pest control

E. A. MacDonald, E. Edwards, J. Balanovic and F. Medvecky,  Wildlife Research,  2020.
Public engagement that acknowledges and responds to these underlying beliefs, rather than a traditional campaign based on biodiversity and environmental gains, may be more effective at creating a constructive dialogue about if and how these tools should be used, and to avoid ...
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Gene Drive Dynamics in Natural Populations: The Importance of Density Dependence, Space, and Sex

S. Dhole, A. L. Lloyd and F. Gould,  Annual Review of Ecology, Evolution, and Systematics,  51:505-531. 2020.
The spread of synthetic gene drives is often discussed in the context of panmictic populations connected by gene flow and described with simple deterministic models. Under such assumptions, an entire species could be altered by releasing a single individual carrying an invasive ...
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Next-generation gene drive for population modification of the malaria vector mosquito, Anopheles gambiae

R. Carballar-Lejarazú, C. Ogaugwu, T. Tushar, A. Kelsey, T. B. Pham, J. Murphy, H. Schmidt, Y. Lee, G. C. Lanzaro and A. A. James,  Proceedings of the National Academy of Sciences,  202010214. 2020.
We show here that the Cas9/guide RNA-based gene-drive components of a genetically-engineered malaria mosquito vector, Anopheles gambiae, achieve key target product profile requirements for efficacy and performance.
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Atypical meiosis can be adaptive in outcrossed Schizosaccharomyces pombe due to wtf meiotic drivers

M. A. Bravo Núñez, I. M. Sabbarini, L. E. Eide, R. L. Unckless and S. E. Zanders,  eLife,  9:e57936. 2020.
Here, we demonstrate that in scenarios analogous to outcrossing, wtf drivers generate a fitness landscape in which atypical spores, such as aneuploids and diploids, are advantageous. In this context, wtf drivers can decrease the fitness costs of mutations that disrupt meiotic ...
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Study Could Lead to Power Over Parasite

D. Shore,  ,  2020.
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 ...
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CRISPR gene drives could eliminate many vector-driven pests and diseases, but challenges remain

J. Champer,  Genetic Literacy Project,  2020.
A functioning gene drive system could fundamentally change our strategies for the control of vector-borne diseases by facilitating rapid dissemination of transgenes that prevent pathogen transmission or reduce vector capacity. CRISPR/Cas9 gene drive promises such a mechanism, ...
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Genomic analyses of a livestock pest, the New World screwworm, find potential targets for genetic control programs

M. 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.
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 ...
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Extensive Recombination Suppression and Epistatic Selection Causes Chromosome-Wide Differentiation of a Selfish Sex Chromosome in Drosophila pseudoobscura

Z. L. Fuller, S. A. Koury, C. J. Leonard, R. E. Young, K. Ikegami, J. Westlake, S. Richards, S. W. Schaeffer and N. Phadnis,  Genetics,  216:205. 2020.
Here, we conduct a multifaceted study of the multiply inverted Drosophila pseudoobscura SR chromosome to understand the evolutionary history, genetic architecture, and present-day dynamics that shape this enigmatic selfish chromosome.
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Artificial Selection Finds New Hypotheses for the Mechanism of Wolbachia-Mediated Dengue Blocking in Mosquitoes

S. A. Ford, I. Albert, S. L. Allen, S. F. Chenoweth, M. Jones, C. Koh, A. Sebastian, L. T. Sigle and E. A. McGraw,  Frontiers in Microbiology,  11:1456. 2020.
We recently used experimental evolution to reveal that Wolbachia-mediated dengue blocking could be selected upon in the A. aegypti host and showed evidence that strong levels of blocking could be maintained by natural selection. In this study, we investigate the genetic variation ...
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Recessive Z-linked lethals and the retention of haplotype diversity in a captive butterfly population

I. J. Saccheri, S. Whiteford, C. J. Yung and A. E. van't Hof,  Heredity,  2020.
Sex chromosomes are predicted to harbour elevated levels of sexually antagonistic variation due to asymmetries in the heritability of recessive traits in the homogametic versus heterogametic sex.
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Gene Drive – The Concept Explained

GeneConvene Global Collaborative,  GeneConvene Global Collaborative,  2020.
This short video is intended to serve as a short tutorial that explains the general idea of 'drive' or 'gene drive' in the context of genetics.  It provides the viewer with a basic understanding of the key genetic processes underlying the patterns of inheritance with which most ...
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Abundance of conserved CRISPR-Cas9 target sites within the highly polymorphic genomes of Anopheles and Aedes mosquitoes

H. Schmidt, T. C. Collier, M. J. Hanemaaijer, P. D. Houston, Y. Lee and G. C. Lanzaro,  Nature Communications,  11. 2020.
ere we report the results of a survey of 1280 genomes of the mosquitoes Anopheles gambiae, An. coluzzii, and Aedes aegypti in which we determine that similar to 90% of all protein-encoding CGD target genes in natural populations include at least one target site with no DRAs at a ...
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A 2017 horizon scan of emerging issues for global conservation and biological diversity

Sutherland, WJB, P.; Broad, S.; Clout, M.; Connor, B.; Cote, I. M.; Dicks, L. V.; Doran, H.; Entwistle, A. C.; Fleishman, E.; Fox, M.; Gaston, K. J.; Gibbons, D. W.; Jiang, Z.; Keim, B.; Lickorish, F. A.; Markillie, P.; Monk, K. A.; Pearce-Higgins, J. W.; Peck, L. S.; Pretty, J.; Spalding, M. D.; Tonneijck, F. H.; Wintle, B. C.; Ockendon, N.,  Trends in Ecology & Evolution,  32:31-40. 2019.
We present the results of our eighth annual horizon scan of emerging issues likely to affect global biological diversity, the environment, and conservation efforts in the future. The potential effects of these novel issues might not yet be fully recognized or understood by the ...
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Split-gene drive system provides flexible application for safe laboratory investigation and potential field deployment

V. L. Del Amo, A. L. Bishop, H. M. Sánchez C, J. B. Bennett, X. Feng, J. M. Marshall, E. Bier and V. M. Gantz,  bioRxiv,  684597. 2019.
CRISPR-based gene drives spread through populations bypassing the dictates of Mendelian genetics, offering a population-engineering tool for tackling vector-borne diseases, managing crop pests, and helping island conservation efforts; unfortunately, current technologies raise ...
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Transmission ratio distortion is frequent in Arabidopsis thaliana controlled crosses

Seymour, DKC, E.; Arioz, B. I.; Koenig, D.; Weigel, D.,  Heredity,  122:294-304. 2019.
The equal probability of transmission of alleles from either parent during sexual reproduction is a central tenet of genetics and evolutionary biology. Yet, there are many cases where this rule is violated. The preferential transmission of alleles or genotypes is termed ...
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Gene drive to reduce malaria transmission in sub-Saharan Africa

A. Burt, M. Coulibaly, A. Crisanti, A. Diabate and J. K. Kayondo,  Journal of Responsible Innovation,  5:S66-S80. 2018.
Gene drive is a natural process by which some genes are inherited at a greater-than-Mendelian rate and can spread through a population even if they cause harm to the organisms carrying them. Many different synthetic gene drive systems have been proposed to suppress the number of ...
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Is it time for synthetic biodiversity conservation?

Piaggio, AJS, G.; Seddon, P. J.; Alphey, L.; Bennett, E. L.; Carlson, R. H.; Friedman, R. M.; Kanavy, D.; Phelan, R.; Redford, K. H.; Rosales, M.; Slobodian, L.; Wheeler, K.,  Trends in Ecology & Evolution,  32:97-107. 2017.
Evidence indicates that, despite some critical successes, current conservation approaches are not slowing the overall rate of biodiversity loss. The field of synthetic biology, which is capable of altering natural genomes with extremely precise editing, might offer the potential ...
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What’s a Gene Drive? And what are the risks and benefits?

Risk Bites,  Arizona State University,  2015.
This video uses ‘white board cartooning’ as a means of illustrating concepts.
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Centromere strength provides the cell biological basis for meiotic drive and karyotype evolution in mice

Chmatal, L., S. I. Gabriel, G. P. Mitsainas, J. Martinez-Vargas, J. Ventura, J. B. Searle, R. M. Schultz and M. A. Lampson,  Current Biology,  24:2295-2300. 2014.
Mammalian karyotypes (number and structure of chromosomes) can vary dramatically over short evolutionary time frames [1-3]. There are examples of massive karyotype conversion, from mostly telocentric (centromere terminal) to mostly metacentric (centromere internal), in 102-10 s ...
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Gene Drive

Wyss Institute,  Harvard University,  2014.
This short video produced by the Wyss Institute and Harvard School of Public Health illustrates in very basic terms the concept of gene drive as distorted patterns of inheritance.
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