| 描述信息 |
Known as the adult-specifier transcription factor in insects, the ecdysone-induced protein 93 (E93) triggers metamorphosis during juvenile-adult transitions in both hemimetabolous and holometabolous insects. While E93 conservatively exists in ametabolous insects, its spatiotemporal expression and physiological function remain poorly understood. In this study, we first discover that in the ametabolous firebrat, Thermobia domestica, the previtellogenic ovary exhibits cyclically high E93 expression, and E93 transcripts mainly locate in the follicular cells surrounding oocytes. Female E93 homozygous mutants exhibit severe fecundity deficiency due to the impaired previtellogenesis. Comparative transcriptomic analyses show that E93 regulates gene expression involved in ECM-receptor interaction during previtellogenesis. Meanwhile, we reveal that in the hemimetabolous cockroach, Blattella germanica, E93 similarly regulates previtellogenic ovarian development; however, E93 is also crucial for fat body function during previtellogenesis. Our results show that the primitive and conserved role of E93 in insects underpins previtellogenesis, while its expression and function underwent evolutionary innovation during the transition from ametaboly to hemimetaboly. |
