Identification of the transcription factor E74A gene from Chilo suppressalis which is essential for vitellogenesis

The most important physiological processes in insects are those related to reproduction and development. Ecdysone is an essential hormone in insects that controls various physiological processes, including reproduction and development. E74A, a subtype of the essential ecdysone-induced transcription factor E74, affects the reproductive systems of many insects. Uncertainty exists regarding the molecular mechanism of E74A in non-model insect reproduction processes. Using bioinformatics analysis, we determined that Chilo suppressalis E74A shared the highest homology with E74 in Ostrinia furnacalis which belongs to the ETS superfamily. By characterizing the spatiotemporal expression profile of CsE74A from different developmental stages and tissues, we found that CsE74A expression levels were highest in female pupae on the 4th day and in the head of female pupa. Knockdown of CsE74A resulted in delayed oocyte maturation and reduced yolk deposition. Additionally, the expression level of vitellogenin (Vg), βFTZ-F1, and E93, which are associated with vitellogenesis and the ecdysone pathway, were also downregulated in the E74A silencing group. Collectively, our findings demonstrate that CsE74A not only plays a critical role in the reproductive processes of C. suppressalis but may also participate in the transcriptional regulation of genes involved in the ecdysone pathway.