Doublesex homolog is sex-specifically spliced and governs the sexual differentiation process in the whitefly Bemisia tabaci AsiaII-1.

[Display omitted] • doublesex gene in Bemisia tabaci Asia II-1 genetic group is composed of six exons and five introns. • These exons are sex specifically spliced forming four male specific transcripts and one female specific transcript. • Btdsx regulates the expression of vitellogenin and vitellogenin receptor in B. tabaci. • dsRNA mediated knockdown of Btdsx in both female and males followed by mating resulted in significant decrease in fecundity and egg hatchability compared to control mating cross. • Knockdown of dsx also resulted in low frequency female specific deformities in the ovipositor. The silverleaf whitefly Bemisia tabaci is one of the most destructive of crop pests globally. In Northern India cotton is predominately infested by the Asia II-1 species of B. tabaci. Though B. tabaci exhibits unique haplodiploidy in its reproductive behavior, to date very little is known regarding its sex determination mechanism. Here, an in-depth characterization of the AsiaII-1 doublesex (Btdsx) gene, which has been implicated in sex determination in B. tabaci , indicates the inclusion of six exons and five introns. The pre-mRNA is shown to sex-specifically splice, producing four male isoforms and one female isoform. These Bt Dsx proteins share common DNA binding (OD1) domains whereas they differ at their C-termini. RT-qPCR analysis revealed a significantly higher expression of Btdsx in female adults compared to that in male adults and earlier developmental stages. Functional characterization of Btdsx through RNA interference (RNAi) resulted in a significant reduction in its expression in both sexes. Btdsx knockdown concomitantly resulted in up-regulation of the expression of vitellogenin (vg) and vitellogenin receptor (vgr) genes in males and their down-regulation in females. Btdsx knockdown followed by mating resulted in reduced fecundity and percent egg hatching; however, no impact was observed on the female: male ratios in the progeny obtained from knockdown parents. [ABSTRACT FROM AUTHOR]