CRISPR/Cas9-Mediated Mutagenesis of Sex-Specific Splicing Variants Leads to Sterility in , a Global Invasive Pest.

(J. E. Smith), an emerging invasive pest worldwide, has posed a serious agricultural threat to the newly invaded areas. Although somatic sex differentiation is fundamentally conserved among insects, the sex determination cascade in is largely unknown. In this study, we cloned and functionally characterized (), a "molecular switch" modulating sexual dimorphism in using male- and female-specific isoforms. Given that Lepidoptera is recalcitrant to RNAi, CRISPR/Cas9-mediated mutagenesis was employed to construct mutants. Specifically, we designed target sites on exons 2, 4, and 5 to eliminate the common, female-specific, and male-specific regions of (), respectively. As expected, abnormal development of both the external and internal genitalia was observed during the pupal and adult stages. Interestingly, knocking out sex-specific variants in led to significantly reduced fecundity and fertility in adults of corresponding sex. Our combined results not only confirm the conserved function of in sex differentiation but also provide empirical evidence for as a potential target for the Sterile Insect Technique (SIT) to combat this globally invasive pest in a sustainable and environmentally friendly way.