Hu Qihao, Xiao Yanhong, Wei Runnan, Tang Ting, Wen Liang, Lu Yuzhen, Yu Xiao-Qiang
Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Guangzhou Key Laboratory of Insect Development Regulation and Application Research, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou, 510631, China.
Insect Sci. 2024 Feb;31(1):79-90. doi: 10.1111/1744-7917.13243. Epub 2023 Jul 18.
Spermatogenesis is a critical part of reproduction in insects; however, its molecular mechanism is still largely unknown. In this study, we identified a testis-specific gene CG3526 in Drosophila melanogaster. Bioinformatics analysis showed that CG3526 contains a zinc binding domain and 2 C H type zinc fingers, and it is clustered to the vertebrate really interesting new gene (RING) family E3 ubiquitin-protein ligases. When CG3526 was knocked down by RNA interference (RNAi), the testis became much smaller in size, and the apical tip exhibited a sharp and thin end instead of the blunt and round shape in the control testis. More importantly, compared to the control flies, only a few mature sperm were present in the seminal vesicle of C587-Gal4 > CG3526 RNAi flies. Immunofluorescence staining of the testis from CG3526 RNAi flies showed that the homeostasis of testis stem cell niche was disrupted, cell distribution in the apical tip was scattered, and the process of spermatogenesis was not completed. Furthermore, we found that the phenotype of CG3526 RNAi flies' testis was similar to that of testis of Stat92E RNAi flies, the expression level of CG3526 was significantly downregulated in the Stat92E mutant flies, and the promoter activity of CG3526 was upregulated by STAT92E. Taken together, our results indicated that CG3526 is a downstream effector gene in the JAK-STAT signaling pathway that plays a key role in the spermatogenesis of Drosophila.
精子发生是昆虫繁殖的关键部分；然而，其分子机制仍 largely 未知。在本研究中，我们在黑腹果蝇中鉴定出一个睾丸特异性基因 CG3526。生物信息学分析表明，CG3526 包含一个锌结合结构域和 2 个 CH 型锌指，并且它聚类到脊椎动物真正有趣的新基因（RING）家族 E3 泛素蛋白连接酶。当通过 RNA 干扰（RNAi）敲低 CG3526 时，睾丸尺寸变得小得多，并且顶端呈现出尖锐和细的末端，而不是对照睾丸中的钝圆形状。更重要的是，与对照果蝇相比，C587-Gal4 > CG3526 RNAi 果蝇的精囊中仅存在少数成熟精子。对 CG3526 RNAi 果蝇的睾丸进行免疫荧光染色显示，睾丸干细胞微环境的稳态被破坏，顶端的细胞分布分散，并且精子发生过程未完成。此外，我们发现 CG3526 RNAi 果蝇睾丸的表型与 Stat92E RNAi 果蝇睾丸的表型相似，CG3526 的表达水平在 Stat92E 突变果蝇中显著下调，并且 CG3526 的启动子活性被 STAT92E 上调。综上所述，我们的结果表明 CG3526 是 JAK-STAT 信号通路中的一个下游效应基因，在果蝇的精子发生中起关键作用。
