Genetic and chemical screening in zebrafish to study tendon development

肌腱将力量从肌肉传递到骨骼，使运动成为可能，柔韧的韧带将骨骼连接起来， 提供稳定。重要的不仅是附件的完整性和强度，而且是 为了有效的运动，肌肉骨骼系统内的连接必须得到严格的调节。体育或 与年龄相关的肌腱或韧带损伤是非常常见的，尽管损伤可能是缓慢的 修复后，肌腱或韧带的原始生物力学性能永远不会完全恢复。尽管 这些组织对移动性是多么重要，我们对它们的分子调控知之甚少 胚胎发育。这个项目的目标是发现调节肌腱和韧带的途径。 胚胎的形成和分化。为了做到这一点，我们将使用斑马鱼，一种强大的基因 和发育脊椎动物模型系统。首先，斑马鱼的头面部肌腱在分子上和 在组织上与哺乳动物的肌腱相似。肌肉和软骨标记物的联合表达研究 显示在肌肉-软骨连接点有肌腱转录本的存在，从而定义了明显的 肌腱细胞群。为了了解斑马鱼肌腱是如何形成的，这项提议将确定 通过功能丧失分析不同的组织类型和已知的信号通路。另外， 转基因斑马鱼将被用于研究肌腱的形成和形态发生 发育时间，这一技术在其他脊椎动物中是不可行的。找出新的路径， 调节肌腱发育，从已知的生物活性化合物库中提取了1000多千克 经过筛选，确定了20个推定的命中。进一步的工作将集中在验证和分析这些问题上 它们在肌腱中的靶向和路径的发展。作为对这一化学筛选的补充，一种前锋 将进行基因筛查，以发现和表征调控肌腱发育的新途径。 这些研究将直接解决肌腱发育生物学领域的主要问题，并可能 最终，有助于开发治疗肌腱或韧带损伤的新疗法。

Tendons transmit force from muscles to bone, enabling movement, wfiile ligaments connect bone to bone, providing stabilization. Not only is the integrity and strength of the attachment important, but the location of the connections within the musculoskeletal system must be strictly regulated for efficient motion. Sports or age-related injuries to tendons or ligaments are extremely common, and although the injury can be slowly repaired, the original biomechanical properties of the tendon or ligament are never fully restored. Despite how essential these tissues are for mobility, we know very little about their molecular regulation during embryonic development. The goal of this project is to discover the pathways regulating tendon and ligament formation and differentiation in the embryo. To accomplish this, we will use the zebrafish, a powerful genetic and developmental vertebrate model system'. First, zebrafish craniofacial tendons are molecularly and histologically similar to mammalian tendons. Co-expression studies with muscle and cartilage markers demonstrate the presence of tendon transcripts at muscle-cartilage connection poi nts, thus defining a distinct population of tendon cells. To understand how zebrafish tendons form, this proposal will determine the role of distinct tissue types and known signaling pathways through loss of function analysis. Additionally, transgenic zebrafish will be generated to study tendon formation and morphogenesis over real developmental time, a technique that is unfeasible in other vertebrates. To identify novel pathways that regulate tendon development, over one thousand com pounds from a known bioactive compound library were screened and 20 putative hits were identified. Further work will focus on the validation and analysis of these hits and the pathways they target in tendon developm ent. Complementing this chemical screen, a forward genetic screen will be performed to discover and characterize new pathways regulating tendon development. These studies will directly address the major questions in the field of tendon developmental biology, and may ultimately, aid in the development of new therapies for tendon or ligament injury.