PDF(Pubmed)
Abstract：
Drosophila spermatogenesis involves the renewal of germline stem cells, meiosis of spermatocytes, and morphological transformation of spermatids into mature sperm. We previously demonstrated that Ocnus (ocn) plays an essential role in spermatogenesis. The ValRS-m (Valyl-tRNA synthetase, mitochondrial) gene was down-regulated in ocn RNAi testes. Here, we found that ValRS-m-knockdown induced complete sterility in male flies. The depletion of ValRS-m blocked mitochondrial behavior and ATP synthesis, thus inhibiting the transition from spermatogonia to spermatocytes, and eventually, inducing the accumulation of spermatogonia during spermatogenesis. To understand the intrinsic reason for this, we further conducted transcriptome-sequencing analysis for control and ValRS-m-knockdown testes. The differentially expressed genes (DEGs) between these two groups were selected with a fold change of ≥2 or ≤1/2. Compared with the control group, 4725 genes were down-regulated (dDEGs) and 2985 genes were up-regulated (uDEGs) in the ValRS-m RNAi group. The dDEGs were mainly concentrated in the glycolytic pathway and pyruvate metabolic pathway, and the uDEGs were primarily related to ribosomal biogenesis. A total of 28 DEGs associated with mitochondria and 6 meiosis-related genes were verified to be suppressed when ValRS-m was deficient. Overall, these results suggest that ValRS-m plays a wide and vital role in mitochondrial behavior and spermatogonia differentiation in Drosophila.
摘要：
果蝇精子发生涉及生殖干细胞的更新，精母细胞减数分裂,精子细胞向成熟精子的形态转化。我们先前证明了Ocnus（ocn）在精子发生中起着至关重要的作用。ValRS-m(Valyl-tRNA合成酶，线粒体）基因在ocnRNAi睾丸中下调。这里,我们发现ValRS-m敲低可诱导雄性果蝇完全不育。ValRS-m的耗竭阻断了线粒体行为和ATP合成，从而抑制从精原细胞到精母细胞的转变，最终，诱导精子发生过程中精原细胞的积累。要理解这其中的内在原因，我们进一步对对照和ValRS-m敲低睾丸进行了转录组测序分析.选择两组之间的差异表达基因（DEGs），其倍数变化≥2或≤1/2。与对照组相比,在ValRS-mRNAi组中,4725个基因下调(dDEGs),2985个基因上调(uDEGs)。dDEGs主要集中在糖酵解途径和丙酮酸代谢途径,UDEGs主要与核糖体生物发生有关。当ValRS-m缺乏时，总共有28个与线粒体相关的DEGs和6个减数分裂相关基因被证实被抑制。总的来说,这些结果表明，ValRS-m在果蝇的线粒体行为和精原细胞分化中起着广泛而重要的作用。
