Key Laboratory of Horticultural Plant Biology (MOE) and State Key Laboratory of Agricultural Microbiology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, People's Republic of China.
China-Australia Joint Research Centre for Horticultural and Urban Pests, Huazhong Agricultural University, Wuhan, Hubei, 430070, People's Republic of China.
Nat Commun. 2020 Feb 18;11(1):932. doi: 10.1038/s41467-020-14622-4.
Regulation of male sexual differentiation by a Y chromosome-linked male determining factor (M-factor) is one of a diverse array of sex determination mechanisms found in insects. By deep sequencing of small RNAs from Bactrocera dorsalis early embryos, we identified an autosomal-derived microRNA, miR-1-3p, that has predicted target sites in the transformer gene (Bdtra) required for female sex determination. We further demonstrate by both in vitro and in vivo tests that miR-1-3p suppresses Bdtra expression. Injection of a miR-1-3p mimic in early embryos results in 87-92% phenotypic males, whereas knockdown of miR-1-3p by an inhibitor results in 67-77% phenotypic females. Finally, CRISPR/Cas9-mediated knockout of miR-1-3p results in the expression of female-specific splice variants of Bdtra and doublesex (Bddsx), and induced sex reversal of XY individuals into phenotypic females. These results indicate that miR-1-3p is required for male sex determination in early embryogenesis in B. dorsalis as an intermediate male determiner.
Y 染色体连锁的雄性决定因子（M 因子）对雄性性别的调控是昆虫中存在的多种性别决定机制之一。通过对黄粉虫早期胚胎小 RNA 的深度测序，我们鉴定出一种常染色体衍生的 microRNA，miR-1-3p，它在性别决定所需的转座子基因（Bdtra）中有预测的靶位点。我们进一步通过体外和体内试验证明，miR-1-3p 抑制 Bdtra 的表达。在早期胚胎中注射 miR-1-3p 模拟物可导致 87-92%的表型雄性，而抑制剂对 miR-1-3p 的敲低则导致 67-77%的表型雌性。最后，CRISPR/Cas9 介导的 miR-1-3p 敲除导致 Bdtra 和 doublesex（Bddsx）的雌性特异性剪接变体的表达，并诱导 XY 个体的性别反转成为表型雌性。这些结果表明，miR-1-3p 作为中间雄性决定因素，在黄粉虫早期胚胎发生中雄性性别决定中是必需的。
