Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China.
Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China.
Insect Biochem Mol Biol. 2019 May;108:1-8. doi: 10.1016/j.ibmb.2019.02.003. Epub 2019 Mar 1.
As a component of the mediator complex, the intersex (ix) gene product is involved in the sex determination pathway of the Drosophila melanogaster. IX functions together with the female-specific product of doublesex (dsx) at the bottom of the hierarchy to implement female sexual differentiation. Here we analyzed the functions of the ix gene in the model lepidopteran insect Bombyx mori. We found that Bmix is expressed in many tissues and is highly expressed in early pupal stages. We used the transgene-based CRISPR/Cas9 system to generate mutants of the Bmix gene. The Bmix female mutants were sterile and had irregular external genitalia, whereas in the mutant males external genitalia were normal. Mutants of both sexes had normal gonad development and normal splicing of the Bmdsx pre-mRNA, suggesting that Bmix functions independently of Bmdsx. Interestingly, both male and female mutants had defective development of the imaginal disc including wing, antenna, and leg. RNA-seq and gene expression analyses indicated that genes involved in WNT, Hippo, and Hedgehog signaling pathways and wing development genes Bmawd and Bmfng were up-regulated or down-regulated in the Bmix mutants compared with wild-type animals. Our data provide insights into the multiple functions of Bmix in female external genital and imaginal disc development in the silkworm.
作为中介复合物的一个组成部分，雌雄同体（ix）基因产物参与了黑腹果蝇的性别决定途径。IX 与性别特异性的 doublesex（dsx）产物一起在层次结构的底部发挥作用，以实现雌性性分化。在这里，我们分析了 ix 基因在模式鳞翅目昆虫家蚕中的功能。我们发现 Bmix 在许多组织中表达，在早期蛹期表达水平较高。我们使用基于转基因的 CRISPR/Cas9 系统生成了 Bmix 基因的突变体。Bmix 雌性突变体不育，外生殖器不规则，而突变体雄性外生殖器正常。雌雄突变体的性腺发育正常，Bmdsx 前体 mRNA 的剪接正常，表明 Bmix 独立于 Bmdsx 发挥作用。有趣的是，雌雄突变体的 imaginal disc 发育都有缺陷，包括翅膀、触角和腿。RNA-seq 和基因表达分析表明，与野生型动物相比，突变体中涉及 WNT、Hippo 和 Hedgehog 信号通路以及翅膀发育基因 Bmawd 和 Bmfng 的基因上调或下调。我们的数据提供了对 Bmix 在雌性外生殖器和 imaginal disc 发育中的多种功能的深入了解。
