CRISPR/Cas9 Mediated Editing of the white (wh) locus Affects Body Size and Reproduction of the Oriental Fruit Fly, Bactocera dorsalis (Hendel)

The Oriental fruit fly Bactrocera dorsalis (Hendel) is a highly significant, invasive pest of fruits which severely affect the global fruit trade. The advent of CRISPR/Cas9 has opened up new avenues for developing futurist management approaches as standalone or complementing other approaches. In this context, numerous earlier studies have documented the mutation of the white locus in B. dorsalis. Studies on Drosophila melanogaster and D. suzukii demonstrated that the white locus (wh) plays a crucial role in pigmentation and various other physiological functions like reproduction. Therefore, in the present study, we have generated a homozygous white eye mutants (wh^−/−) bearing a four base pair deletion and studied the possible effects on the biological attributes such as reproductive fitness and body size as compared to the wild flies. A single pair of adults produced significantly lesser offsprings (5.80 ± 3.67 pupae) in the cross involving wh^−/−♀ × wh^−/−♂ than in the WT♀ × WT♂ cross (21.80 ± 3.91 pupae). The morphometric analysis showed that wh^−/− individuals exhibited a reduced overall body size compared to wild-type males and females. Also, there was an overall increase in the life cycle of wh^−/− individuals (23.20 ± 0.47 days) as compared to WT individuals (19.20 ± 0.51 days). This study provides comprehensive insights into the effects of the white gene mutation and provide potential avenues for future research on devising novel management strategies against B. dorsalis.