GAP JUNCTIONS DURING EMBRYONIC BONE FORMATION

描述：本申请的长期目标是获得 更深入地了解胚胎骨的机制 阵缝隙连接介导细胞的作用及意义 将在成骨细胞表达期间评价通信。 表型在胚胎鸡下颌间充质。这些研究 最近的研究结果支持了这一点， 两种缝隙连接蛋白与胚胎骨形成的关系 面部原基这两种间隙连接蛋白，连接蛋白43和 连接蛋白45主要与骨的两个方面相关 阵 骨形成的启动与连接蛋白43有关 分化成骨细胞的渐进性表达， 表型与连接蛋白45相关。 因为这是唯一的 已发现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， 应用将集中在连接蛋白表达和间隙的作用， 连接介导的细胞通讯在建立 成骨谱系。提出了四个具体目标。 第一特定 目的是确定是否需要间隙连接通信， 成骨表型的表达。第二个具体目标是 确定间隙连接通信的干扰是否将 改变成骨表型。 第三个具体目标是确定 Cx43和Cx45的mRNA表达是否在发育过程中 监管. 第四个具体目标是确定 特异性细胞粘附分子（CAM）的出现与 成骨间质中Cx43或Cx45的表达。 所使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 细胞负载技术

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.