Author response: Development of a confinable gene drive system in the human disease vector Aedes aegypti

AbstractAedes albopictus mosquitoes are important vectors for a number of human pathogens including the Zika, dengue, and chikungunya viruses. Capable of displacing Aedes aegypti populations, it adapts to cooler environments which increases its geographical range and transmission potential. There are limited control strategies for Aedes albopictus mosquitoes which is likely attributed to the lack of comprehensive biological studies on this emerging vector. To fill this void, here using RNAseq we characterized Aedes albopictus mRNA expression profiles at 47 distinct time points throughout development providing the first high-resolution comprehensive view of the developmental transcriptome of this worldwide human disease vector. This enabled us to identify several patterns of shared gene expression among tissues as well as sex-specific expression patterns. Moreover, to illuminate the similarities and differences between Aedes aegypti, a related human disease vector, we performed a comparative analysis using the two developmental transcriptomes. We identify life stages were the two species exhibited significant differential expression among orthologs. These findings provide insights into the similarities and differences between Aedes albopictus and Aedes aegypti mosquito biology. In summary, the results generated from this study should form the basis for future investigations on the biology of Aedes albopictus mosquitoes and provide a goldmine resource for the development of transgene-based vector control strategies.

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Genomic insertion locus and Cas9 expression in the germline affect CRISPR/Cas9-based gene drive performance in the yellow fever mosquito Aedes aegypti

10.1101/2021.12.08.471839 ◽

2021 ◽

Author(s):

William R Reid ◽

Jingyi Lin ◽

Adeline E Williams ◽

Rucsanda Juncu ◽

Ken E Olson ◽

...

Keyword(s):

Aedes Aegypti ◽

Yellow Fever ◽

Drive System ◽

Gene Drive ◽

Yellow Fever Mosquito ◽

Genomic Locus ◽

Population Replacement ◽

Novel Approach ◽

Drive Systems ◽

Insertion Locus

The yellow fever mosquito Aedes aegypti is a major vector of arthropod-borne viruses, including dengue, chikungunya, and Zika. A novel approach to mitigate arboviral infections is to generate mosquitoes refractory to infection by overexpressing antiviral effector molecules. Such an approach requires a mechanism to spread these antiviral effectors through a population, for example, by using CRISPR/Cas9-based gene drive systems. Here we report an autonomous single-component gene drive system in Ae. aegypti that is designed for persistent population replacement. Critical to the design of a single-locus autonomous gene drive is that the selected genomic locus be amenable to both gene drive and the appropriate expression of the antiviral effector. In our study, we took a reverse engineering approach to target two genomic loci ideal for the expression of antiviral effectors and further investigated the use of three promoters for Cas9 expression (nanos, β2-tubulin, or zpg) for the gene drive. We found that both promoter selection and genomic target site strongly influenced the efficiency of the drive, resulting in 100% inheritance in some crosses. We also observed the formation of inheritable gene drive blocking indels (GDBI) in the genomic locus with the highest levels of gene drive. Overall, our drive system forms a platform for the further testing of driving antipathogen effector genes through Ae. aegypti populations.

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A CRISPR endonuclease gene drive reveals two distinct mechanisms of inheritance bias

10.1101/2020.12.15.421271 ◽

2020 ◽

Author(s):

Sebald A.N. Verkuijl ◽

Estela González ◽

Joshua Xin De Ang ◽

Ming Li ◽

Nikolay P Kandul ◽

...

Keyword(s):

Aedes Aegypti ◽

Homing Endonuclease ◽

Meiotic Drive ◽

Drive System ◽

Transgene Inheritance ◽

Gene Drive ◽

Tight Linkage ◽

Multiple Species ◽

Gene Drives ◽

Endonuclease Gene

RNA guided CRISPR gene drives have shown the capability of biasing transgene inheritance in multiple species. Among these, homing endonuclease drives are the most developed. 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. Additionally, by making use of the tight linkage of white to the sex-determining locus, we were able to elucidate mechanisms of inheritance bias. We find inheritance bias through homing in double heterozygous males, but find that a previous report of the same drive occurred through meiotic drive. We propose that other previously reported 'homing' design gene drives may in fact bias their inheritance through other mechanisms with important implications for gene drive design.

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The Developmental Transcriptome of Aedes albopictus, a Major Worldwide Human Disease Vector

G3 Genes|Genome|Genetics ◽

10.1534/g3.119.401006 ◽

2020 ◽

Vol 10 (3) ◽

pp. 1051-1062 ◽

Cited By ~ 6

Author(s):

Stephanie Gamez ◽

Igor Antoshechkin ◽

Stelia C. Mendez-Sanchez ◽

Omar S. Akbari

Keyword(s):

Gene Expression ◽

Aedes Aegypti ◽

Aedes Albopictus ◽

Human Disease ◽

Control Strategies ◽

Expression Profiles ◽

Expression Patterns ◽

Disease Vector ◽

Biological Studies ◽

Similarities And Differences

Aedes albopictus mosquitoes are important vectors for a number of human pathogens including the Zika, dengue, and chikungunya viruses. Capable of displacing Aedes aegypti populations, this mosquito adapts to cooler environments which increases its geographical range and transmission potential. There are limited control strategies for Aedes albopictus mosquitoes which is likely attributed to the lack of comprehensive biological studies on this emerging vector. To fill this void, here using RNAseq we characterized Aedes albopictus mRNA expression profiles at 34 distinct time points throughout development providing the first high-resolution comprehensive view of the developmental transcriptome of this worldwide human disease vector. This enabled us to identify several patterns of shared gene expression among tissues as well as sex-specific expression patterns. To illuminate the similarities and differences with Aedes aegypti, a related human disease vector, we also performed a comparative analysis between the two developmental transcriptomes, identifying life stages where the two species exhibit similar and distinct gene expression patterns. These findings provide insights into the similarities and differences between Aedes albopictus and Aedes aegypti mosquito biology. In summary, the results generated from this study should form the basis for future investigations on the biology of Aedes albopictus and provide a gold mine resource for the development of transgene-based vector control strategies.

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Development and testing of a novel killer–rescue self-limiting gene drive system in Drosophila melanogaster

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2019.2994 ◽

2020 ◽

Vol 287 (1925) ◽

pp. 20192994 ◽

Cited By ~ 5

Author(s):

Sophia H. Webster ◽

Michael R. Vella ◽

Maxwell J. Scott

Keyword(s):

Drosophila Melanogaster ◽

Aedes Aegypti ◽

Drive System ◽

R Gene ◽

Agricultural Pest ◽

Gene Drive ◽

Wild Type ◽

Drosophila Suzukii ◽

Population Replacement ◽

Population Suppression

Here we report the development and testing of a novel self-limiting gene drive system, Killer–Rescue (K–R), in Drosophila melanogaster . This system is composed of an autoregulated Gal4 Killer (K) and a Gal4-activated Gal80 Rescue (R). Overexpression of Gal4 is lethal, but in the presence of R activation of Gal80 leads to much lower levels of Gal4 and rescue of lethality. We demonstrate that with a single 2 : 1 engineered to wild-type release, K drives R through the population and after nine generations, more than 98% of the population carry R and less than 2% of the population are wild-type flies. We discuss how this simple K–R gene drive system may be readily adapted for population replacement in a human health pest, Aedes aegypti , or for population suppression in an agricultural pest, Drosophila suzukii .

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