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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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.
A Code of Ethics for Gene Drive Research
16379G. J. Annas, C. L. Beisel, K. Clement, A. Crisanti, S. Francis, M. Galardini, R. Galizi, J. Grünewald, G. Immobile, A. S. Khalil, R. Müller, V. Pattanayak, K. Petri, L. Paul, L. Pinello, A. Simoni, C. Taxiarchi and J. K. Joung, The CRISPR Journal, 4:19:1-8. 2021-02-10 14:57:13.
A code of ethics can be a useful tool for all parties involved in the development and regulation of gene drives and can be used to help ensure that a balanced analysis of risks, benefits, and values is taken into consideration for the interest of society and humanity. We have developed a code of ethics for gene drive research with the hope that this code will encourage the development of an international framework that includes ethical guidance of gene drive research and is incorporated into scientific practice by gaining broad agreement and adherence.
In Our Image: The Ethics of CRISPR Genome Editing
16272J. C. Eissenberg, Biomolecular Concepts, 12:1-7. 2021-02-06 16:55:38.
Here, I discuss the ethics surrounding the transformative CRISPR/Cas9mediated genome editing technology in the contexts of human genome editing to eradicate genetic disease and of gene drive technology to eradicate animal vectors of human disease.
How to engage communities on a large scale? Lessons from World Mosquito Program in Rio de Janeiro, Brazil [version 2; peer review: 1 approved, 2 approved with reservations]
16361G. B. Costa, R. Smithyman, S. L. O'Neill and L. A. Moreira, Gates Open Research, 2021-02-04 19:26:09.
Here we discuss and analyse the framework for community engagement implemented by the WMP in Brazil, during the large-scale deployment of the method in the municipalities of Niterói and Rio de Janeiro, Brazil. Our experience indicates that the community engagement work for arboviruses control should be understood as an opportunity for local development. It is necessary, based on an integrated analysis of the territory, to understand that the actions for arboviruses control could be a catalyst for the necessary socioenvironmental, cultural and public health changes. Furthermore, it is essential to understand that community engagement goes beyond informing or asking for population consent, but it constitutes a possibility for dialogue and exchange between the various stakeholders present in the territories, to build on cooperation for mosquito-borne disease control.
Reply to: Issues with combining incompatible and sterile insect techniques
16265Y. Li, L. A. Baton, D. Zhang, J. Bouyer, A. G. Parker, A. A. Hoffmann, L. C. Ng, C. H. Tan and Z. Xi, Nature, 590:E3-E5. 2021-02-04 16:31:29.
When the aim is elimination of the target population, Uni-CI and Bi-CI do not have appreciably different risks of population replacement. The small-scale field trial8 cited by Moretti and Calvitti in their Comment1 does not provide evidence that Bi-CI protects against population replacement during IIT, as the occurrence of the released Wolbachia strain in the field was not determined and the level of population suppression was insufficient to facilitate surpassing of the invasion threshold.
The complete mitogenome sequence of the agricultural pest, clover root weevil: the key to its own demise?
18799R. A. Al-Jiab, J. Gillum, A. Alexander, D. M. Tompkins, C. B. Phillips, P. K. Dearden and N. J. Gemmell, Mitochondrial DNA Part B, 4:878-879. 2021-02-03 18:44:34.
AbstractWe report the complete mitogenome of Sitona obsoletus, an agricultural pest in New Zealand and some European countries. Like other Sitona mitogenomes, the 6 tRNA gene box is ordered RNSAEF, supporting the hypothesis that this signature is common to, and potentially diagnostic, of this genus. The Trojan Female Technique (TFT) is a genetic pest control strategy that exploits mitochondrial DNA alleles that affect male, but not female fertility and fitness. The complete mitogenome is an essential first step in exploring the utility of TFT for the control of S. obsoletus.
Issues with combining incompatible and sterile insect techniques
16261R. Moretti and M. Calvitti, Nature, 590:E1-E2. 2021-02-03 16:00:45.
In a recent paper, Zheng at al.1 performed field experiments that tested a strategy of mosquito suppression based on the release of functionally sterile males produced by the combination of reproductive unidirectional cytoplasmic incompatibility (which is induced by the bacterium Wolbachia) and a sterilization treatment caused by X-rays. In our opinion, the authors do not present an exhaustive description of the current status in this field, and their results highlight several practical weaknesses in this strategy.
Improving the Phenotypic Properties of the Ceratitis capitata (Diptera: Tephritidae) Temperature-Sensitive Lethal Genetic Sexing Strain in Support of Sterile Insect Technique Applications
16226M. F. Porras, J. S. Meza, E. G. Rajotte, K. Bourtzis and C. Caceres, Journal of Economic Entomology, 113:2688-2694. 2021-01-31 16:33:01.
We present the first evidence that this slower development is due to a different gene, here namely slow development (sd), which is closely linked to the tsl gene. Taking advantage of recombination phenomena between the two loci, we report the isolation of a novel temperature sensitivity lethal strain using the wp mutation as a morphological marker, which showed faster development (wp tsl FD) during the larval stage and increased in its temperature sensitivity compared with the normal tsl strain. Moreover, the introgression of this novel wp tsl FD combined trait into the Vienna 8(D53-) GSS, resulted in a novel Vienna 8(D53-) FD GSS, where females showed differences in the thermal sensibility, larval development speed, and productivity profiles. The modification of these traits and their impact on the mass rearing of the GSS for sterile insect technique applications are discussed.
Regulating the expression of gene drives is key to increasing their invasive potential and the mitigation of resistance
16290A. 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. 2021-01-29 21:53:25.
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.
Sexual Competitiveness and Induced Egg Sterility by Aedes aegypti and Aedes albopictus Gamma-Irradiated Males: A Laboratory and Field Study in Mexico
17760J. G. Bond, S. Aguirre-Ibáñez, A. R. Osorio, C. F. Marina, Y. Gómez-Simuta, R. Tamayo-Escobar, A. Dor, P. Liedo, D. O. Carvalho and T. Williams, Insects, 12. 2021-01-29 14:44:07.
The sterile insect technique may prove useful for the suppression of mosquito vectors of medical importance in regions where arboviruses pose a serious public health threat. In the present study, we examined the effects of sterilizing irradiation doses across different ratios of fertile:irradiated males on the mating competitiveness of Ae. aegypti and Ae. albopictus under laboratory and field-cage conditions. For both species, the percentage of females inseminated and the number of eggs laid over two gonotrophic cycles varied significantly in mating treatments involving 1:1, 1:5, and 1:10 fertile:irradiated males compared to controls of entirely fertile or entirely irradiated males but was not generally affected by the irradiation dose. Egg hatching was negatively affected in females exposed to increasing proportions of irradiated males in both laboratory and field cages. Male competitiveness (Fried’s index) values varied from 0.19 to 0.58 in the laboratory and were between 0.09 and 1.0 in field cages, depending on th species. Competitiveness values were negatively affected by th eirradiation dose in both species under field-cage conditions, whereas in the laboratory, Ae. albopictus was sensitive to the dose but Ae. aegypti was not. In general, male competitiveness was similar across all mating regimes. Most importantly, induced egg sterility was positively correlated with the proportion of irradiated males present in the mating treatments, reaching a maximum of 88% under field-cage conditions for both Ae. aegypti and Ae. albopictus males treated with 50 and 40 Gy irradiation, respectively. These results indicate that sterile males produced at our facility are suitable and competitive enough for field pilot SIT projects and provide guidance to decide the optimal sterile:fertile ratios.
GENE DRIVE ACCEPTANCE SURVEY
16233YouGov, Pollinis, 2021-01-27 16:47:37.
This representative survey was conducted by the international market research institute YouGov and polled 8.826 citizens from 8 EU countries in December 2020. It was commissioned by WeMove Europe, Save Our Seeds (Germany), Skiftet (Sweden), France Nature Environnement (FNE) (France), POLLINIS (France), OGM Dangers (France), Bund für Umwelt und Naturschutz (BUND) (Germany), Deutscher Naturschutzring (DNR) (Germany), Umweltinstitut München (Germany), Za Zemiata (Bulgaria). Deviations from 100% are due to rounding.
Demographic feedbacks can hamper the spatial spread of a gene drive
16203L. Girardin and F. Débarre, arXiv, 2021-01-27 15:32:53.
Our results indicate that taking into account the interplay between population dynamics and population genetics might actually be crucial, as it can effectively reverse the direction of the invasion and lead to failure. Our findings can be extended to other bistable systems, such as the spread of cytoplasmic incompatibilities caused by Wolbachia.
Playing God and tampering with nature: popular labels for real concerns in synthetic biology
16201L. Carter, A. Mankad, E. V. Hobman and N. B. Porter, Transgenic Research, 2021-01-27 15:26:41.
We present the findings from a large Australian study (N = 4593) which suggests ‘playing God’ objections and their variants can be multilayered and, at times, accompanied by meaningful information about risk perceptions. We use qualitative analysis of ope
Anopheles gambiae Genome Conservation as a Resource for Rational Gene Drive Target Site Selection
16102N. Kranjc, A. Crisanti, T. Nolan and F. Bernardini, Insects, 12. 2021-01-23 14:46:16.
In this study we describe a bioinformatic pipeline that allows the analysis of whole genome data for the identification of highly conserved regions that can point at potential functional or structural constraints. The analysis was conducted across the genomes of 22 insect species separated by more than hundred million years of evolution and includes the observed genomic variation within field caught samples of Anopheles gambiae and Anopheles coluzzii, the two most dominant malaria vectors. This study offers insight into the level of conservation at a genome-wide scale as well as at per base-pair resolution.
Drivers of mosquito mating
16110N. C. Manoukis, Science, 371:340. 2021-01-22 15:54:49.
Gene drive systems are based on the release of organisms whose genomes have been modified or engineered to spread a desired allele or trait (such as resistance to the parasites that cause malaria) through a population. Success will depend on the release of genetically modified males that will be able to mate with wild females. Beyond gene drive strategies, in mosquitoes it is understood that only males can be released as part of any genetic pest control (GPC) program (7); females feed on blood to lay eggs, and releasing insects that will feed on humans is widely unacceptable.
Clock genes and environmental cues coordinate Anopheles pheromone synthesis, swarming, and mating
16108G. Wang, J. Vega-Rodríguez, A. Diabate, J. Liu, C. Cui, C. Nignan, L. Dong, F. Li, C. O. Ouedrago, A. M. Bandaogo, P. S. Sawadogo, H. Maiga, T. L. Alves e Silva, T. V. Pascini, S. Wang and M. Jacobs-Lorena, Science, 371:411. 2021-01-22 15:35:30.
Knockdown of per and tim expression affects Anopheles gambiae s.s. and Anopheles stephensi male mating in the laboratory, and it reduces male An. coluzzii swarming and mating under semifield conditions. Light and temperature affect mosquito mating, possibly by modulating per and/or tim expression. Moreover, the desaturase gene desat1 is up-regulated and rhythmically expressed in the heads of swarming males and regulates the production of cuticular hydrocarbons, including heptacosane, which stimulates mating activity.
The Promises and Realities of Integration in Synthetic Biology: A View From Social Science
16287L. Carter and A. Mankad, Frontiers in Bioengineering and Biotechnology, 8. 2021-01-21 17:25:32.
We take stock of thepromises and realities of science integration by sharing our experiences of embarking onthis very challenge in Australia. We conclude by offering suggestions for bringing aboutthe enabling conditions for improved integration across the natural and social sciences.Four key actions are articulated to help pivot synthetic biology toward a more integratedscientific endeavor: (a) formalizing inclusivity from inception to project conclusion; (b)valuing differing philosophical positions as a strength rather than a barrier; (c) acceptingthat integration takes persistence and communication but is immensely rewarding; and(d) promoting meaningful interactions, such as pursuing joint opportunities, co-designingand co-publishing research. We argue that these actions arekey enablers for realizingscience integration in synthetic biology.
White pupae phenotype of tephritids is caused by parallel mutations of a MFS transporter
16691C. M. Ward, R. A. Aumann, M. A. Whitehead, K. Nikolouli, G. Leveque, G. Gouvi, E. Fung, S. J. Reiling, H. Djambazian, M. A. Hughes, S. Whiteford, C. Caceres-Barrios, T. N. M. Nguyen, A. Choo, P. Crisp, S. B. Sim, S. M. Geib, F. Marec, I. Hacker, J. Ragous, Nature Communications, 12. 2021-01-21 15:50:54.
Here, we use classical and modern genetic approaches to identify and functionally characterize causal wp(-) mutations in these distantly related fruit fly species. We find that the wp phenotype is produced by parallel mutations in a single, conserved gene. CRISPR/Cas9-mediated knockout of the wp gene leads to the rapid generation of white pupae strains in C. capitata and B. tryoni. The conserved phenotype and independent nature of wp(-) mutations suggest this technique can provide a generic approach to produce sexing strains in other major medical and agricultural insect pests. The white pupae (wp) phenotype has been used for decades to selectively remove females of tephritid species in genetic sexing, but the determining gene is unknown. Here, the authors show that wp phenotype is produced by parallel mutations in a Major Facilitator Superfamily domain containing gene across multiple species.
Co‐developing a common glossary with stakeholders for engagement on new genetic approaches for malaria control in a local African setting
16104E. Chemonges Wanyama, B. Dicko, L. Pare Toe, M. B. Coulibaly, N. Barry, K. Bayala Traore, A. Diabate, M. Drabo, J. K. Kayondo, S. Kekele, S. Kodio, A. D. Ky, R. R. Linga, E. Magala, W. I. Meda, S. Mukwaya, A. Namukwaya, B. Robinson, H. Samoura, K. Sanogo, Malaria Journal, 20:53. 2021-01-21 14:51:47.
Scientific terminologies are mainly lacking in local languages, yet when research activities involve international partnership, the question of technical jargon and its translation is crucial for effective and meaningful communication with stakeholders. Target Malaria, a not-for-profit research consortium developing innovative genetic approaches to malaria vector control, carried out a linguistic exercise in Mali, Burkina Faso and Uganda to establish the appropriate translation of its key terminology to local languages of sites where the teams operate.
Combining refuges with transgenic insect releases for the management of an insect pest with non-recessive resistance to Bt crops in agricultural landscapes
17006T. R. Brewer and M. B. Bonsall, Journal of Theoretical Biology, 509:11. 2021-01-21 12:35:03.
Reinforcing the high-dose/refuge strategy with releases of transgenic insects has been suggested as a method for simultaneously managing agricultural pest populations and resistance to transgenic crops. Theoretical and empirical studies have shown that these approaches can work when deployed against closed populations and the assumptions of the HDR strategy are met. However, field-evolved resistance is often linked to non-recessive resistance or refuge non-compliance, and pest management regimes are likely to take place at the landscape-level. It is therefore important to understand how effective such strategies are when resistance is non-recessive, and how they could be employed in agricultural landscapes. We developed a spatially-explicit model to investigate the efficacy of strategies combining refuges with transgenic insect releases to manage a pest with non-recessive resistance in agricultural landscapes. We compared two release strategies, area-wide releases and localised releases targeted at population hotspots, and analysed the effects of refuge and release parameters on population and resistance dynamics. Area-wide releases reliably achieved landscape-level pest eradication. Localised releases also eradicated the pest when low release thresholds were combined with high release ratios, and maintained the pest at low densities when insufficient to achieve extinction. Reinforcing refuges with localised releases also greatly enhanced the probability of resistance extinction. However, when resistance remained in the population, localised releases prevented resistance from reaching fixation rather than greatly delaying or reversing resistance evolution. Our work indicates that combining refuges with simple release policies is effective for landscape-level pest suppression when the HDR assumptions are violated, but more nuanced release strategies may be required to enhance the benefits to resistance management. (C) 2020 Elsevier Ltd. All rights reserved.
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