Chen Peng, Tong Xiao-Ling, Fu Ming-Yue, Hu Hai, Song Jiang-Bo, He Song-Zhen, Gai Ting-Ting, Dai Fang-Yin, Lu Cheng
State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China.
Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing 400716, China.
Sci Rep. 2016 Jan 7;6:18956. doi: 10.1038/srep18956.
The morphological diversity of insects is important for their survival; in essence, it results from the differential expression of genes during development of the insect body. The silkworm apodal (ap) mutant has degraded thoracic legs making crawling and eating difficult and the female is sterile, which is an ideal subject for studying the molecular mechanisms of morphogenesis. Here, we confirmed that the infertility of ap female moths is a result of the degradation of the bursa copulatrix. Positional cloning of ap locus and expression analyses reveal that the Bombyx mori sister of odd and bowl (Bmsob) gene is a strong candidate for the ap mutant. The expression of Bmsob is down-regulated, while the corresponding Hox genes are up-regulated in the ap mutant compared to the wild type. Analyses with the dual luciferase assay present a declined activity of the Bmsob promoter in the ap mutant. Furthermore, we demonstrate that Bmsob can inhibit Hox gene expression directly and by suppressing the expression of other genes, including the BmDsp gene. The results of this study are an important contribution to our understanding of the diversification of insect body plan.
昆虫的形态多样性对其生存至关重要；本质上，它是昆虫身体发育过程中基因差异表达的结果。家蚕无腹足（ap）突变体的胸足退化，导致爬行和进食困难，且雌蛾不育，这是研究形态发生分子机制的理想对象。在此，我们证实ap雌蛾不育是交配囊退化的结果。ap基因座的定位克隆和表达分析表明，家蚕odd和bowl的同源基因（Bmsob）是ap突变体的有力候选基因。与野生型相比，ap突变体中Bmsob的表达下调，而相应的Hox基因上调。双荧光素酶分析表明，ap突变体中Bmsob启动子的活性下降。此外，我们证明Bmsob可以直接抑制Hox基因的表达，并通过抑制包括BmDsp基因在内的其他基因的表达来实现。本研究结果对我们理解昆虫身体结构的多样性具有重要贡献。
