MicroRNAs (miRNAs) are a class of short, non‐coding transcripts that bind to 3′‐untranslated regions to trigger messenger RNA degradation or translational inhibition. Here we explored how miRNAs regulate sex determination in Bombyx mori, a lepidopteran model insect. Genes known to be involved in sex determination, BmPSI, Bmdsx, and BmMasc, are predicted targets of the species‐specific miR‐2738. Using a dual luciferase reporter assay in HEK293T cells, we confirmed that miR‐2738 suppressed transcription of BmPSI, Bmdsx, and BmMasc. The levels of BmPSI and BmMasc were significantly down‐regulated in B. mori miR‐2738 overexpression. In contrast, the genetic disruption of miR‐2738 using the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR‐associated protein 9 transgenic system increased the levels of BmPSI and BmMasc transcripts, whereas splicing of Bmdsx was unaltered by miR‐2738 depletion or overexpression. Taken together, this study implicates miR‐2738 as a minor regulator of sex determination genes in the silkworm.

中文翻译：

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microRNA-2738 调控家蚕性别决定通路中的基因表达

MicroRNA (miRNA) 是一类短的非编码转录物，可与 3' 非翻译区结合以触发信使 RNA 降解或翻译抑制。在这里，我们探讨了 miRNA 如何调节家蚕（一种鳞翅目模式昆虫）的性别决定。已知参与性别决定的基因 BmPSI、Bmdsx 和 BmMasc 是物种特异性 miR-2738 的预测目标。在 HEK293T 细胞中使用双荧光素酶报告基因检测，我们证实 miR-2738 抑制了 BmPSI、Bmdsx 和 BmMasc 的转录。BmPSI 和 BmMasc 的水平在 B. mori miR-2738 过表达中显着下调。相比之下，使用成簇的规则间隔短回文重复序列 (CRISPR)/CRISPR 相关蛋白 9 转基因系统对 miR-2738 的遗传破坏增加了 BmPSI 和 BmMasc 转录物的水平，而 Bmdsx 的剪接不受 miR-2738 耗尽或过度表达的影响。总之，这项研究表明 miR-2738 是家蚕性别决定基因的次要调节因子。