Gu Licheng, Guo Mujuan, Wang Pengzhan, Zhao Jianchao, Wu Zhiwei, Wang Zihan, Zhang Sijie, Yang Xin, Ma Ruofei, Wang Lizhi, Ye Xiqian, Huang Jianhua, Chen Xue-Xin, Wang Zhizhi
Institute of Insect Sciences, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China.
Ministry of Agriculture and Rural Affairs Key Lab of Molecular Biology of Crop Pathogens and Insect Pests, Zhejiang University, Hangzhou, China.
Cell Mol Life Sci. 2025 Apr 28;82(1):183. doi: 10.1007/s00018-025-05717-6.
Parasitoids modulate host development for the survival of their offspring, but the mechanisms underlying this phenomenon remain largely unknown. Here, we found that the endoparasitoid Cotesia vestalis disrupted the larval-larval ecdysis in its host Plutella xylostella by the 20-hydroxyecdysone (20E) synthesis pathway. After parasitization by C. vestalis, the 20E peak of host larvae disappeared before the onset of ecdysis and the expression of ecdysone synthesis genes was significantly downregulated. We further found that a Cotesia vestalis bracovirus (CvBV) gene CvBV_28 - 5 was transiently high-level expressed prior to the host's 20E peak, enabling the precise suppression of this critical developmental signal. Consistently, the knockdown of CvBV_28 - 5 affected the expression of 20E response transcription factors in the cuticle and several ecdysis-related genes. Furthermore, we found that CvBV_28 - 5 bound directly to the Raf, a MAP3K member of the MAPK pathwaythat functions as a critical regulator of ecdysone synthesis genes in hosts. Collectively, our results provide the first evidence that parasitoids modulate host ecdysis by affecting MAPK-20E signaling during a defined developmental window and provide novel insights into the mechanism of parasitoid regulation of host development.
寄生蜂会调节宿主的发育以确保其后代的存活，但这种现象背后的机制在很大程度上仍不为人知。在此，我们发现内寄生蜂菜蛾盘绒茧蜂通过20-羟基蜕皮激素（20E）合成途径扰乱其宿主小菜蛾的幼虫-幼虫蜕皮过程。被菜蛾盘绒茧蜂寄生后，宿主幼虫的20E峰值在蜕皮开始前消失，且蜕皮激素合成基因的表达显著下调。我们进一步发现，菜蛾盘绒茧蜂杆状病毒（CvBV）基因CvBV_28 - 5在宿主的20E峰值出现之前短暂地高水平表达，从而能够精确抑制这一关键的发育信号。一致地，敲低CvBV_28 - 5会影响表皮中20E应答转录因子以及几个与蜕皮相关基因的表达。此外，我们发现CvBV_28 - 5直接与Raf结合，Raf是丝裂原活化蛋白激酶（MAPK）途径中的一个丝裂原活化蛋白激酶3（MAP3K）成员，在宿主中作为蜕皮激素合成基因的关键调节因子发挥作用。总体而言，我们的结果首次证明了寄生蜂在特定的发育窗口期间通过影响MAPK - 20E信号传导来调节宿主蜕皮，并为寄生蜂调节宿主发育的机制提供了新的见解。
