Identification of molecular mechanisms regulating skeletal morphology

脊椎动物骨骼提供多种重要功能，包括形态、强度、柔韧性和保护重要器官。骨骼复杂形态的建立需要骨形成细胞和关节形成细胞的分化协调生长。事实上，关于细胞如何分裂以及相关细胞类型如何分化，我们已经知道了很多。然而，对于这些事件是如何协调产生正确大小和形状的骨骼元素，人们知之甚少。间隙连接蛋白Cx43在斑马鱼鳍再生过程中调节细胞增殖和关节形成，表明Cx43同时协调生长和定形。为了确定Cx43如何介导这些活性，使用分子遗传学方法鉴定了假定的靶基因。从这个目标基因列表中验证的Cx43依赖基因将被放置在Cx43下游作用的基因的有序途径中。因此，这将有可能揭示在鳍的生长和图案形成过程中由Cx43调节的阶阶分子途径。这一建议的智力价值在于，将揭示对骨骼形状和图案形成的机制见解。前50个目标基因的验证将在一个新的基于探究的本科生实验课程中部分完成。因此，这一提议的更广泛的影响包括为大量学生提供科学实践的机会，同时也提供了一套发育生物学的核心实验室技能。该建议充分整合了智力价值和更广泛的影响，既推进了骨骼形态发生的知识领域，又为如何在实验室环境中解决复杂的生物学问题提供了指导。

The vertebrate skeleton provides a variety of important functions including form, strength, flexibility, and protection of vital organs. Establishment of the complex form of the skeleton requires the coordination of growth with the differentiation of bone-forming cells and joint-forming cells. Indeed, much is known about how cells divide and about how relevant cell types differentiate. However, very little is understood about how these events are coordinated to give rise to skeletal elements of the correct size and shape. The gap junction protein Cx43 has been shown to regulate both cell proliferation and joint formation during zebrafish fin regeneration, revealing that Cx43 coordinates growth and patterning concomitantly. To determine how Cx43 mediates these activities, putative target genes were identified using a molecular genetics approach. Validated Cx43-dependent genes from this list of target genes will be placed in an ordered pathway of genes acting downstream of Cx43. Thus, it will be possible to reveal the step-wise molecular pathway(s) regulated by Cx43 during growth and patterning of the fin. The intellectual merit of this proposal is that mechanistic insights into the establishment of skeletal form and patterning will be revealed. Validation of the top 50 target genes will be completed in part during a new inquiry-based laboratory course for undergraduates. Thus, the broader impacts of this proposal include providing a large number of students access to the practice of science while also providing a set of core laboratory skills in Developmental Biology. The intellectual merit and the broader impacts are fully integrated in this proposal, both advancing the field of knowledge of skeletal morphogenesis and providing instruction on how to solve complex biological problems in a laboratory setting.