Hedgehog参与西伯利亚鲟侧线机械和电感受器分化的初始证据

THE INITIAL EVIDENCE FOR HEDGEHOG SIGNALING INVOLVED IN THE DIFFERENTIATION OF MECHANORECEPTORS AND ELECTRORECEPTORS IN THE LATERAL LINE SYSTEM IN SIBERIAN STURGEON

为揭示Hedgehog(Hh)信号与神经丘和壶腹器官分化的关系,研究以西伯利亚鲟(Acipenser baerii Brandt)为模型,首先对再生过程中的神经丘和壶腹器官的转录组进行比较分析,发现Hh信号通路关键基因(Shh、Patched 1)在两类感受器中差异表达,且它们的表达在再生过程中呈现动态性。然后用环巴胺(Cyclopamine,Hh信号抑制剂)处理西伯利亚鲟胚胎(st29),用扫描电镜和FM1-43荧光染色对西伯利亚鲟仔鱼(st43-st44)分析发现环巴胺显著抑制了壶腹器官的发育。整体原位杂交表明,Shh、Patched1、Smoothened、Gli2在腹面侧线区域的表达受到了环巴胺的抑制。以上结果暗示Hh信号通路与神经丘和壶腹器官的发育有关,推测Hh信号在神经丘和壶腹器官的分化过程中起到了重要作用。

The lateral line system of some amphibians, all chondrichthyan and non-neopterygian fish is consisted of mechanoreceptors and electroreceptors that are originated from lateral line placodes. However, the molecular mechanism of mechanoreceptor and electroreceptor differentiation remains unclear. Hedgehog is a critical morphogen for pattern formation and stem cell differentiation of multiple organs. In this study, we investigated the relationship between hedgehog signaling and the differentiation of neuromast and ampullary organ in Siberian sturgeon. We found dynamic expression of Shh and Patched1 via the transcriptome analysis in regenerating neuromast and ampullary organ. Furthermore, inhibiting hedgehog signaling by cyclopamine from stage 29 to stage 37 reduced the number of ampullary organs specifically. In addition, cyclopamine repressed the expression of Shh, Patched1, Smoothened, and Gli2 in the ventral region of head. These results indicated that hedgehog signaling was related with the development ampullary organ in Siberian sturgeon.