The ZcVg3 gene regulates the reproduction and lifespan of female Zeugodacus cucurbitae (Coquillett) mediated by short-term high temperature

BACKGROUND: Zeugodacus cucurbitae (Coquillett), a significant pest of fruit and vegetable in tropical and subtropical regions, is influenced by short-term high temperatures in its development and reproduction. Vitellogenin (Vg) is an essential precursor of yolk protein formation in eggs and plays a vital role in ovarian development of insect. Interfering Z. cucurbitae vitellogenin receptor ( ZcVgR ) gene in short-term high temperature background decreases the fecundity of female adults, while the transcription level of the ZcVg3 gene increases. To elucidate the reproductive function of the ZcVg3 gene and the synergistic relationship among ZcVgs genes in short-term high temperature, this study injected siRNA to interfere ZcVg3 gene after subjecting Z. cucurbitae to a 1 h treatment at 45°C and 25°C. RESULTS: The expression of the ZcVg3 gene was suppressed, leading to a down-regulation of ZcVgR gene and an up-regulation of ZcVg1 gene. Silencing ZcVg3 gene after a 1 h treatment at 45°C resulted in a reduction of approximately 84.7% and 75.9% in the fecundity and spawning days of female adults compared to control check. The development rate of their ovaries and ovarian diameter significantly decreased, and their lifespan was reduced by 71%. CONCLUSIONS: ZcVg3 gene plays a crucial role in the reproduction of Z. cucurbitae in short-term high temperature background. The results of this study provide potential targets for the development of RNAi-based techniques for controlling Z. cucurbitae .