GENETIC AND MOLECULAR BASIS OF CARDIAC NEURAL CREST IN DEVELOPING CHICK EMBRYO

心脏神经嵴在支持发育方面是独一无二的 心脏和主动脉弓的动脉。 贝弗莉·伊曼纽尔博士和 同事们已经证明，从人类中缺失22 q11区域， 22号染色体导致儿童的一系列缺陷， 在小鸡中模仿去除迁移前的心脏神经 冠。 这些缺陷也存在于16三体小鼠中， 包含人类22 q11对应区域的重复。 我的目标是确定基因产物的功能意义 从22 q11的神经嵴相关的心脏发育。 实验 该缺失的模型将使用由以下产生的嵌合体来建立： 16三体小鼠胚胎心脏神经嵴移植 感染到正常的小鸡宿主上 这些嵌合体胚胎将通过 项目3和4，用于适当的神经嵴迁移， 增殖、细胞外基质变异和最终心血管疾病 表型。 利用该模型，可以对22 q11缺失基因的功能进行分析。 可以预测。 22 q11微缺失的探针将用于 从鸡胚中筛选心脏神经嵴富集的cDNA文库。 将对阳性克隆进行测序，并用于北方和原位 鸡胚心血管病关键期发育分析 发展 最后，那些编码信息的cDNA被发现， 在功能上和时空上与来自 小鼠-小鸡嵌合模型将用于消融或过度消融。 在鸡胚中的表达研究。

The cardiac neural crest is unique in its ability to support development of the heart and aortic arch arteries. Dr. Beverly Emmanuel and colleagues have demonstrated that deletion of the region 22q11 from human chromosome 22 results in a spectrum of defects in children that can be mimicked in the chick of removal of the premigratory cardiac neural crest. These defects are also present in the trisomy 16 mouse which contains duplication of the regions corresponding to 22q11 in humans. My goal is to identify the functional significance of the gene products from 22q11 in neural crest related heart development. An experimental model of this deletion will be established using chimeras produced from transplantation of cardiac neural crest from trisomy 16 mouse embryos onto normal chick hosts. These chimeric embryos will be analyzed by projects 3 and 4 for appropriate neural crest migration and proliferation, extracellular matrix variations and final cardiovascular phenotype. Using this model the function of the deleted genes in 22q11 can be predicted. Probes for the 22q11 microdeletion will be used to screen cardiac neural crest-enriched cDNA libraries from chick embryos. Positive clones will be sequenced and used for Northern and in situ analysis of developing chick embryos at critical stages of cardiovascular development. Finally, those cDNAs that code for messages found to correlate functionally and spatiotemporally with information derived from the mouse-chick chimeric model will be used in ablation or over expression studies in chick embryos.