Origins of Cardiac Neural Crest in the Chick Epiblast

描述(由申请人提供)： 在神经管阶段，预期的心脏神经脊位于后脑的背侧，这是一个为心脏大动脉做出贡献的细胞群。然而，在神经褶形成之前，尚无关于上皮样细胞中假定的心脊细胞的来源和承诺状态的信息。本研究的目的是：1)确定鸡外胚层中预期的心脏神经峰的位置；2)确定该细胞群在外胚层中的定位。初步结果表明，在原肠胚期4，心脏神经脊前体沿前后轴尚未与其他脊相分离。我的下一个实验将致力于识别第四阶段到第九阶段之间的心脊前体。由于心脏神经脊与其他神经脊不同，在神经管阶段9之前就注定了它的命运，所以我推测心脊可能在神经管阶段之前就已经出现了。我将使用DIL标记、电穿孔、鹌鹑/小鸡移植和延时成像来解决上面列出的目标。这一建议将进一步加深我们对心脏神经脊形成的理解，并为心脏脊诱导的分子表征铺平道路。

DESCRIPTION (provided by applicant): The prospective cardiac neural crest, a cell population that contributes to the great arteries of the heart, resides in the dorsal aspect of the hindbrain at neural tube stages. However, no information is available on the origin and state of commitment of presumptive cardiac crest cells in the epiblast before neural fold formation. This proposal aims to 1) identify the location of prospective cardiac neural crest in the epiblast in chick, 2) determine the state of commitment of this cell population in the epiblast. Preliminary results suggest that, at gastrula stage 4, cardiac neural crest precursors are not yet segregated from other crest along the anterior posterior axis. My next experiments will aim at identifying the cardiac crest precursors between stage 4 and stage 9. Because the cardiac neural crest, unlike other neural crest, is committed to its fate by neural tube stage 9, I hypothesize that the cardiac crest might already be committed before neural tube stage. I will use Dil labeling, electroporation, quail/chick grafts and time-lapse imaging to resolve the aims listed above. This proposal will further our understanding of the formation of cardiac neural crest and pave the way to a molecular characterization of the induction of the cardiac crest.