EXTRACELLULAR MOLECULAR INTERACTION IN LIMB DEVELOPMENT

该项目的中心主题是概念性的。具体来说，我们 认为肢体形态发生源于内在机制 间充质，可由分泌的形态因子外在调节 邻近的组织。我们认为，要阐明这些机制，关键是 特定的内源性肢体分子被识别出来 各种肢体表型的表达。我们特别想找出 用来建立组织组织的主要模式的蛋白质 在此基础上进行肢体形态形成。高分辨分子 将使用各种方法从结构和功能上描述 特定的蛋白质(有些已经在手中)对血统的影响 肢体间充质的限制、表型表达和组织形成 细胞。所有项目都使用3D文化系统，在该系统中，子种群 可以分离或探测间充质细胞对组织起源的反应 感应信号。所有项目要么包括分子克隆，要么包括 染色质结构分析。对于每个项目，包括以下两个分子 克隆或染色质结构分析。对于每个项目，请具体说明 已经提出了一些假设。在项目I中(马克瓦尔德/克鲁格/博伦德) 将检测外胚层分泌的蛋白质(例如Es-I抗原) 它们对软骨形成的调节影响的影响(包括 初级成软骨中心数量的调节和组织发生 胶原蛋白凝胶中间充质前体细胞群之间的相互作用 文化。在项目III(Godfrey)中，基底膜分子的作用 在细胞分化之前发现的间充质细胞将具有功能 测试它们在肌细胞分化、肌管形成和肌细胞分化中的作用(S) 突触发生。对于其中的一种，agrin，cdna克隆将用于 包括外胚层相互作用在内的发育调节的研究。在……里面 项目四(法伦)，将进行活体分析以测试这些角色 外胚层的图案化机制，而3D胶原凝胶培养将 用于建立顶端外胚层脊功能的生物测定方法 无肢(11个)和无翼突变体。项目I和项目IV的成果 将与从模式缺陷的塔尔比德2获得的结果进行比较 变种人。法伦博士和他的合作者特明博士将继续他们的研究 正在进行的研究开发一种用于细胞标记的鸡可遗传标记 项目I和项目IV的实验：三个核心单元，初级培养核心 (Bolender)、单抗核心(York De)和EM细胞化学核心 (Riley)和一个管理核心将提供研究 有技术和概念支持的项目。对世界经济的热情 计划保持较高水平，因为进展导致了 我们可以用来进行跨学科研究的程序和分子探针 努力阐明肢体形态发生的机制。

The central theme of this program project is conceptual. Specifically, we propose that limb morphogenesis proceeds from intrinsic mechanisms within mesenchyme which can be extrinsically modulated by morphogens secreted by adjacent tissues. We believe to elucidate these mechanisms, it is critical that specific endogenous limb molecules be identified that coordinate expression of the various limb phenotypes. We especially seek to identify proteins that serve to establish the primary pattern of tissue organization upon which limb morphogenesis proceeds. High resolution molecular approaches will be used to structurally and functionally characterize specific proteins (some already in hand) for their effects on lineage restriction, phenotypic expression and tissue formation of limb mesenchymal cells. All projects utilize a 3.d culture system in which subpopulations of mesenchyme can be isolated or probed for response to histogenic inductive signals. All projects include either molecular cloning or chromatin structural analyses. For each projects include either molecular cloning or chromatin structural analyses. For each project, specific hypotheses have been proposed. In Project I (Markwald/Krug/Bolender) ectodermally secreted proteins (e.g. ES-I antigens) will be assayed for effects for their regulatory influence on chondrogenesis (including regulation of the number of primary chondrogenic centers) nd histogenic interactions between mesenchymal precursor cell populations in collagen gel culture. In Project III (Godfrey) the role of basement membrane molecules found on mesenchymal cells before cytodifferentiation will be functionally tested for their role(s) in myogenic differentiation, myotube formation and synaptogenesis. For one of these, agrin, cDNA clones will be obtained for studies of developmental regulation including ectodermal interaction. In Project IV (Fallon), in vivo analyses will be performed to test the roles of ectoderm in patterning mechanisms while the 3d collagen gel culture will be used to establish bioassays of apical ectodermal ridge function using limbless (11) and wingless mutants. Results from both Projects I and IV will compared with findings obtained from the pattern deficient Talpid 2 mutant. Dr. Fallon and his collaborator, Dr. Temin, will continue their ongoing studies to develop a chick heritable marker for use in cell marking experiments in Projects I and IV. Three core units, Primary Culture Core (Bolender), Monoclonal Antibody Core (Yorde) and the EM Cytochemical Core (Riley) along with an Administrative Core will provide the research projects with both technical and conceptual support. Enthusiasm for the program remains high as progress has resulted in the development of procedures and molecular probes with which we can pursue interdisciplinary efforts to elucidate mechanisms of limb morphogenesis.