Discovering Mechanisms Underlying the Formation of a Straight Body Axis

项目摘要/摘要： 线形头尾体轴是如何在发育过程中形成并在生长过程中保持的，这方面的研究很少 明白了。轴向矫直中的缺陷--形成线性轴的形态形成过程-- 导致结构性出生缺陷和脊柱弯曲，如脊柱侧弯。在这个提案中，我们使用了易处理的 斑马鱼系统，以发现形成和维持线性体轴的潜在原理。斑马鱼 胚胎最初是弯曲的，围绕着一团蛋黄，但在受精后大约32小时，胚胎 轴线已经拉直，可以产生一只自主游泳的幼虫。轴向伸直需要活动的纤毛， 它在中央管内跳动并产生脑脊液(CSF)流。纤毛击打结果异常 在伸直失败的情况下，幼虫保持腹侧曲线。使用一种新的双突变系，在目标1 我们确定了纤毛运动下游神经肽Urp1和Urp1的作用机制。 这将严格检验轴向伸直依赖于尾加压素肽的模型，并建立 新的脊柱侧弯动物模型。接下来，我们评估伸直轴线的形态发生运动如何停止 准确地说是在生成直轴的时候。在PKD2突变胚胎中，这种停止过程失败，导致 背部曲线异常。在目标2和目标3中，我将确定PKD2在 控制轴线性度。在目标2中，我将测试PKD2调节纤毛非依赖性过程的假设 控制背部肌肉收缩，为形成性身体运动提供力量。在目标3中，我 将测试脊索的作用，脊索是身体中心的一根硬棒，一旦它是直立的，它就会保持直立。 以及PKD2在该组织中的潜在作用。总体而言，我的工作将发现如何 多个组织-中央管、背侧躯体肌内活动的纤毛/脑脊液/神经元界面，以及 脊索轴-生成线性主体轴的坐标。这项工作将对理解 生物体的正确解剖是如何通过自组织过程产生的，这是很重要的 以了解结构性出生缺陷的起源和再生医学。我的工作将使用一个范围 并为我提供了细胞和发育生物学方面的严格训练。

PROJECT SUMMARY/ ABSTRACT: How the linear head-to-tail body axis forms during development and is then maintained during growth is little understood. Defects in axial straightening — the morphogenetic process through which a linear axis forms — result in structural birth defects and spinal curves such as scoliosis. In this proposal, we use the tractable zebrafish system to discover principles underlying the formation and maintenance of a linear body axis. Zebrafish embryos are initially curved ventrally around a ball of yolk but, by around 32 hours post fertilization, the embryonic axis has straightened to produce an autonomously swimming larva. Axial straightening requires motile cilia, which beat and generate cerebrospinal fluid (CSF) flow in the central canal. Abnormalities in cilia beating result in a failure of straightening, with larvae maintaining ventral curves. Using a novel double mutant line, in Aim 1 we determine mechanisms underlying the function of neuropeptides Urp1 and Urp1 downstream of cilia motility. This will rigorously test the model that axial straightening depends on Urotensin peptides as well as establish new animal models for scoliosis. Next, we assess how morphogenetic movements that straighten the axis stop precisely when a straight axis is generated. In pkd2 mutant embryos, this stopping process fails, leading to abnormal dorsal curves. In Aims 2 and 3, I will determine the mechanisms through which Pkd2 functions in controlling axial linearity. In Aim 2, I will test the hypothesis that Pkd2 regulates cilia-independent processes that control the dorsal muscle contractions which supply the force for morphogenetic body movements. In Aim 3, I will test the role of the notochord, a stiff rod down the center of the body, in maintaining straightness once it is generated, and the potential role of Pkd2 in this tissue. Overall, my work will discover new principles of how multiple tissues — the motile cilia/CSF/neuronal interface within the central canal, dorsal somitic muscle, and the notochord — coordinate to generate a linear body axis. This work will have implications for understanding how the correct anatomy of an organism is generated through self-organizing processes, something important for understanding the origin of structural birth defects and for regenerative medicine. My work will use a range of innovative techniques and provide me with a rigorous training in cell and developmental biology.