Department of Entomology, Nanjing Agricultural University, Nanjing, China.
Insect Mol Biol. 2020 Apr;29(2):193-204. doi: 10.1111/imb.12620. Epub 2019 Nov 2.
The endosymbiont Wolbachia is known for manipulating host reproduction in selfish ways. However, the molecular mechanisms have not yet been investigated in embryos. Here, we found that Wolbachia had no effect on the number of deposited eggs in Tetranychus urticae Koch (Acari: Tetranychidae) but caused two types of reproductive manipulation: killing uninfected female embryos via cytoplasmic incompatibility (CI) and increasing the hatching ratio of infected female embryos. RNA sequencing analyses showed that 145 genes were differentially expressed between Wolbachia-infected (WI) and Wolbachia-uninfected (WU) embryos. Wolbachia infection down-regulated messenger RNA (mRNA) expression of glutathione S-transferase that could buffer oxidative stress. In addition, 1613 and 294 genes were identified as CI-specific up-/down-regulated genes. Compared to WU and WI embryos, embryos of CI cross strongly expressed genes involved in transcription, translation, tissue morphogenesis, DNA damage and mRNA surveillance. In contrast, most of the genes associated with energy production and metabolism were down-regulated in the CI embryos compared to the WU and WI embryos, which provides some clues as to the cause of death of CI embryos. These results identify several genes that could be candidates for explaining Wolbachia-induced CI. Our data form a basis to help elucidate the molecular consequences of CI in embryos.
共生菌沃尔巴克氏体以自私的方式操纵宿主繁殖。然而，其在胚胎中的分子机制尚未被研究。在这里，我们发现沃尔巴克氏体对十字花科植物全爪螨（蜱螨目：叶螨科）的产卵数量没有影响，但会导致两种类型的生殖操纵：通过细胞质不亲和（CI）杀死未感染的雌性胚胎，以及增加感染雌性胚胎的孵化率。RNA 测序分析表明，沃尔巴克氏体感染（WI）和未感染（WU）胚胎之间有 145 个基因的表达存在差异。沃尔巴克氏体感染下调了谷胱甘肽 S-转移酶的信使 RNA（mRNA）表达，该酶可以缓冲氧化应激。此外，还鉴定出 1613 个和 294 个基因分别为 CI 特异性上调和下调基因。与 WU 和 WI 胚胎相比，CI 交叉胚胎强烈表达参与转录、翻译、组织形态发生、DNA 损伤和 mRNA 监测的基因。相比之下，与 WU 和 WI 胚胎相比，CI 胚胎中与能量产生和代谢相关的大多数基因下调，这为 CI 胚胎死亡的原因提供了一些线索。这些结果确定了几个可能解释沃尔巴克氏体诱导的 CI 的候选基因。我们的数据为阐明胚胎中 CI 的分子后果提供了基础。
