St Amand T R, Ra J, Zhang Y, Hu Y, Baber S I, Qiu M, Chen Y
Department of Cell and Molecular Biology, Tulane University, New Orleans, Louisiana 70118, USA.
Biochem Biophys Res Commun. 1998 Jun 9;247(1):100-5. doi: 10.1006/bbrc.1998.8740.
Asymmetry along the left-right axis of the embryo is a vital feature of vertebrate embryogenesis. In this study, we report the isolation and characterization of a bicoid-related homeobox gene, cPitx2, which displays left-right asymmetric expression during early chick embryogenesis. Asymmetric expression of cPitx2 is first detected at stage 7 and is restricted to mesodermal tissues on the left side of the embryo including the left sided lateral mesoderm, the left sided precardiac mesoderm, and the left half epimyocardium of the primitive heart. cPitx2 is also detected in the presumptive blood islands and endothelia of the embryonic blood vessels. Implantation of Sonic hedgehog (SHH) protein soaked beads on the right side of embryos induced ectopic cPitx2 expression on that side. Based on these observations, we suggest that cPitx2 is a component in SHH signaling pathway and plays a role in determining left-right asymmetry and in vasculogenesis during avian embryogenesis.
胚胎左右轴上的不对称是脊椎动物胚胎发育的一个重要特征。在本研究中，我们报告了一个与双尾相关的同源框基因cPitx2的分离和特性，该基因在鸡胚胎早期发育过程中表现出左右不对称表达。cPitx2的不对称表达最早在第7阶段被检测到，并局限于胚胎左侧的中胚层组织，包括左侧外侧中胚层、左侧心前中胚层和原始心脏的左半部分心外膜。cPitx2也在胚胎血管的假定血岛和内皮中被检测到。将浸泡过音猬因子（SHH）蛋白的珠子植入胚胎右侧可诱导该侧异位cPitx2表达。基于这些观察结果，我们认为cPitx2是SHH信号通路的一个组成部分，在鸟类胚胎发育过程中在确定左右不对称和血管生成中发挥作用。
