Enrichment of phenotype among biological forms of Anopheles stephensi Liston through establishment of isofemale lines.

Background: Vector management programs rely on knowledge of the biology and genetic make-up of mosquitoes. Anopheles stephensi is a major invasive urban malaria vector, distributed throughout the Indian subcontinent and Middle East, and has recently been expanding its range in Africa. With the existence of three biological forms, distinctly identifiable based on the number of ridges on eggs and varying vectorial competence, An.

Reversing insecticide resistance with allelic-drive in Drosophila melanogaster.

A recurring target-site mutation identified in various pests and disease vectors alters the voltage gated sodium channel (vgsc) gene (often referred to as knockdown resistance or kdr) to confer resistance to commonly used insecticides, pyrethroids and DDT. The ubiquity of kdr mutations poses a major global threat to the continued use of insecticides as a means for vector control. In this study, we generate common kdr mutations in isogenic laboratory Drosophila strains using CRISPR/Cas9 editing.

Efficient allelic-drive in Drosophila.

Gene-drive systems developed in several organisms result in super-Mendelian inheritance of transgenic insertions. Here, we generalize this "active genetic" approach to preferentially transmit allelic variants (allelic-drive) resulting from only a single or a few nucleotide alterations. We test two configurations for allelic-drive: one, copy-cutting, in which a non-preferred allele is selectively targeted for Cas9/guide RNA (gRNA) cleavage, and a more general approach, copy-grafting, that permits selective inheritance of a desired allele located in close proximity to the gRNA cut site.