GAP JUNCTIONS DURING EMBRYONIC BONE FORMATION

描述：此应用程序的长期目标是获得一个 更深入地了解胚胎骨骼的机制 队形。缝隙连接介导的细胞的作用和意义 在表达成骨细胞的过程中将评估沟通 鸡胚下颌间充质的表型。这些研究是 最近的发现支持了这一点，即 胚胎中存在两种与骨形成相关的缝隙连接蛋白 面部原始物。这两种缝隙连接蛋白分别是缝隙连接蛋白43和 连接蛋白45主要与骨骼的两个方面有关 队形。成骨的启动与连接蛋白43有关 分化成骨细胞的进行性表达 表型与连接蛋白45相关。因为这是唯一的 已发现的与骨形成相关的连接蛋白，以及 由于这些连接蛋白表现出的特异性，这 应用将重点放在连接蛋白表达和GAP的作用上 连接介导的细胞通讯在细胞内的建立 成骨血统。提出了四个具体目标。第一个具体 目的是确定是否需要缝隙连接通信 成骨表型的表达。第二个具体目标是 确定是否会干扰缝隙连接通信 改变成骨表型。第三个具体目标是确定 Cx43和Cx45的mRNA表达是否为发育性 受监管的。第四个具体目标是确定 特异性细胞黏附分子(CAM)的出现与 Cx43和Cx45在成骨间质中的表达 可利用的技术包括显微外科手术、组织重组、 细胞和器官培养，显微注射，组织化学， 免疫细胞化学、原位杂交、化学和机械 细胞加载技术。

DESCRIPTION: The long range goal of this application is to acquire a deeper understanding of the mechanisms that underlie embryonic bone formation. The role and significance of gap junction-mediated cell communication will be evaluated during expression of the osteogenic phenotype in embryonic chick mandibular mesenchyme. These studies are supported by recent findings of a specific association between the presence of two gap junction proteins with bone formation in embryonic facial primordia. These two gap junction proteins, connexin43 and connexin45, are associated principally with two aspects of bone formation. The initiation of osteogenesis is associated with connexin43 and the progressive expression of the differentiating osteogenic phenotype is associated with connexin45. Since these are the only connexins that have been found associated with bone formation, and because of the specificity exhibited by these connexins, this application will focus on the role of connexin expression and of gap junction-mediated cell communication in the establishment of the osteogenic lineage. Four specific aims are proposed. The first specific aim is to determine whether gap junctional communication is required for expression of the osteogenic phenotype. The second specific aim is to determine whether interference with gap junctional communication will alter the osteogenic phenotype. The third specific aim is to determine whether the expression of mRNA for Cx43 and Cx45 is developmentally regulated. The fourth specific aim is to determine whether the appearance of specific cell adhesion molecules (CAMs) is associated with the expression of either Cx43 or Cx45 in osteogenic mesenchyme. Techniques to be utilized include microsurgery, tissue recombination, cell and organ culture, microinjection, histochemistry, immunocytochemistry, in situ hybridization, and chemical and mechanical cell-loading techniques.