Pleiotropic Roles of the Orthologue of the Gene in the Brown Planthopper.

(), a gene involved in the sex-determining cascade of , works in concert with the female-specific product of () at the end of the hierarchy to implement the sex-specific differentiation of sexually dimorphic characters in female individuals. In this study, the homolog was identified in the brown planthopper (BPH), , which contained two splice variants expressed in both female and male insects. We found that played a vital role in the early nymphal development of BPH, showing an accumulated effect. RNAi-mediated knockdown of at 4th instar led to the external genital defects in both sexes, consequently resulting in the loss of reproductive ability in female and male individuals. After dsRNA injection, the males were normal on testes, while the females had defective ovarian development. was also required for early embryogenesis. Notably, when the ds microinjection was performed in newly emerged females, the copulatory bursas were abnormally enlarged while the other tissues of the reproductive system developed normally. Our results demonstrated the pleiotropic roles of in embryogenesis and development of the reproductive system in a hemimetabolous insect species.