Hu Rui-Ying, Xu Peng, Chen Yue-Lei, Lou Xin, Ding Xiaoyan
Laboratory of Molecular Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Graduate School of the Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China.
Biochem Biophys Res Commun. 2006 Jun 23;345(1):239-47. doi: 10.1016/j.bbrc.2006.04.068. Epub 2006 Apr 25.
Vertebrate inner ear develops from its rudiment, otic placode, which later forms otic vesicle and gives rise to tissues comprising the entire inner ear. Although several signaling molecules have been identified as candidates responsible for inner ear specification and patterning, many details remain elusive. Here, we report that Paraxial Protocadherin (PAPC) is required for otic vesicle formation in Xenopus embryos. PAPC is expressed strictly in presumptive otic placode and later in otic vesicle during inner ear morphogenesis. Knockdown of PAPC by dominant-negative PAPC results in the failure of otic vesicle formation and the loss of early inner ear markers Sox9 and Tbx2, suggesting the requirement of PAPC in the early stage of otic vesicle development. However, PAPC alone is not sufficient to induce otic placode formation.
脊椎动物的内耳由其原基耳板发育而来，耳板随后形成耳泡，并产生构成整个内耳的组织。尽管已经鉴定出几种信号分子作为负责内耳特化和模式形成的候选分子，但许多细节仍然难以捉摸。在这里，我们报告说，在非洲爪蟾胚胎中，近轴原钙黏蛋白（PAPC）是耳泡形成所必需的。在胚胎内耳形态发生过程中，PAPC只在预定的耳板中特异性表达，随后在耳泡中表达。通过显性负性PAPC敲低PAPC会导致耳泡形成失败以及早期内耳标记物Sox9和Tbx2的缺失，这表明PAPC在耳泡发育的早期阶段是必需的。然而，单独的PAPC不足以诱导耳板的形成。
