Abstract：
Paired box (Pax) genes are highly conserved throughout evolution, and the Pax protein is an important transcription factor of embryonic development. The Pax gene Bmgsb is expressed in the silk glands of silkworm, but its biological functions remain unclear. This study aimed to investigate the expression pattern of Bmgsb in the silk gland and explore its functions using RNA interference (RNAi). Here, we identified eight Pax genes in Bombyx mori. Phylogenetic analysis showed that the B. mori Pax genes were highly homologous to the Pax genes in other insects and highly evolutionarily conserved. The tissue expression profile showed that Bmgsb was expressed in the anterior silk gland and anterior part of the middle silk gland (AMSG). RNAi of Bmgsb resulted in defective development of the AMSG, and the larvae were mostly unable to cocoon in the wandering stage. RNA-seq analysis showed that the fibroin genes fib-l, fib-h and p25, cellular heat shock response-related genes and phenol oxidase genes were considerably upregulated upon Bmgsb knockdown. Furthermore, quantitative reverse transcription-PCR results showed that the fibroin genes and ubiquitin proteolytic enzyme-related genes were significantly upregulated in the AMSG after Bmgsb knockdown. This study provides a foundation for future research on the biological functions of B. mori Pax genes. In addition, it demonstrates the important roles of Bmgsb in the transcriptional regulation of fibroin genes and silk gland development.
摘要：
配对盒（Pax）基因在整个进化过程中高度保守，而Pax蛋白是胚胎发育的重要转录因子。pax基因Bmgsb在家蚕的丝腺中表达，但其生物学功能尚不清楚。本研究旨在研究Bmgsb在丝腺中的表达模式，并利用RNA干扰（RNAi）探讨其功能。这里,我们在家蚕中鉴定了8个Pax基因。系统发育分析表明，在其他昆虫中，B.moriPax基因与Pax基因高度同源，在进化上高度保守。组织表达谱显示Bmgsb在前丝腺和前中丝腺(AMSG)中均有表达。Bmgsb的RNAi导致AMSG的发育缺陷，幼虫在游荡阶段大多无法茧。RNA-seq分析显示丝心蛋白基因fib-l,在Bmgsb敲低后，fib-h和p25，细胞热休克反应相关基因和酚氧化酶基因显着上调。此外，定量反转录-PCR结果显示,Bmgsb基因敲低后,AMSG中丝素蛋白基因和泛素蛋白水解酶相关基因显著上调。本研究为进一步研究B.moripax基因的生物学功能奠定了基础。此外,证明了Bmgsb在丝素基因转录调控和丝腺发育中的重要作用。
