ETIOLOGY AND DEVELOPMENT OF CONGENITAL HEART DISEASE

这项研究的长期目标是获得一个完整的 了解两种疾病背后的遗传和分子机制 先天性心脏病的遗传形式：圆锥动脉干缺陷（CTD） 和动脉导管未闭（PDA）。 这些将在胚胎中进行研究， 胎儿的独特线条是人类缺陷的精确模型。 在CTD行中，将检验以下特定假设：1. 圆锥动脉干隔发育异常，产生心室 间隔缺损、法洛四联症或永存动脉干， 与右心室生长的普遍失败有关 早期胚胎心肌肌球蛋白表达异常 受累心肌中的心室轻链; 3）单个主要 基因突变是CTD线缺陷的基础，该基因可能具有 与肌球蛋白基因座相同或连锁。 在PDA产品线中， 将检验以下假设：1）内膜增厚失败 在动脉导管未闭胎儿的动脉导管中， 一种遗传决定的透明质酸积累障碍 (HA)动脉内膜下区域; 2）动脉粥样硬化（DA）特异性蛋白 最近在血管内皮细胞和平滑肌细胞中发现的分子 正常羔羊DA存在于正常的狗DA中，但一个或两个都不存在 遗传性动脉粥样硬化性贫血的狗 使用的方法包括定量 心肌有丝分裂细胞的形态计量学和BrdU标记， 胎心垫状组织分布分析 用蛋白质凝胶法研究胚胎和胎儿心肌肌球蛋白轻链 电泳（1D，2D PAGE）和针对这些蛋白质，DNA 限制性片段长度多态性（RFLP）研究 CTD基因与肌球蛋白基因和其它基因的连锁。 PDA研究 包括胎儿HA的免疫组织化学和生物化学分析 和新生儿动脉导管内膜增厚期间，细胞培养 DA、肺动脉和主动脉的放射性标记蛋白的分析 通过SDS PAGE和放射自显影法测定细胞，以及使用单特异性抗体 原位研究导管特异性蛋白的分布。

The long term objective of this research is to obtain a complete understanding of the genetic and molecular mechanisms underlying two hereditary forms of congenital heart disease: Conotruncal defects (CTDs) and patent ductus arteriosus (PDA). These will be studied in embryos and fetuses of unique lines that are accurate models of the human defects. In the CTD line, the following specific hypotheses will be tested: 1. Abnormal development of the conotruncal septum, producing ventricular septal defect, tetralogy of Fallot, or persistent truncus arteriosus, is associated with a generalized failure of growth of right ventricular myocardium in early embryos; 2) There is abnormal expression of myosin ventricular light chains in the affected myocardium; 3) A single major gene mutation underlies the CTD line defect and this gene may have identity with or be linked to myosin gene loci. In the PDA line, the following hypotheses will be tested: 1) The failure of intimal thickening in the ductus arteriosus of affected PDA line fetuses is associated with a genetically-determined block in the accumulation of hyaluronic acid (HA) in the subintimal region; 2) Ductus arteriosus (DA) specific protein molecules recently identified in endothelial and smooth muscle cells of the normal lamb DA are present in normal dog DA but one or both is absent in the hereditary PDA line dogs. Methods to be used include quantitative morphometry and BrdU-labelling of mitotic cells of the myocardium and cushion tissue of the embryonic heart, analysis of the distribution of myosin light chains in embryonic and fetal myocardium using protein gel electrophoresis (1D, 2D PAGE) and antibodies against these proteins, DNA Southern blot restriction fragment length polymorphism (RFLP) studies of linkage of the CTD gene to myosin genes and other genes. PDA studies include immunohistochemical and biochemical analysis of HA in the fetal and neonatal ductus arteriosus during intimal thickening, cell cultures analysis of radiolabeled proteins of DA, pulmonary artery, and aortic cells by SDS PAGE and autoradiography, and use of monospecific antibodies to study the distribution of the ductus-specific proteins in situ.