Genetic Analysis of the Zebrafish Somitogenesis Oscillator

振荡在生物学中是常见的，如生物钟、心脏起搏器、大脑皮层节律，并作为反馈环的结果在细胞信号网络中观察到。这些细胞和生理振荡维持动态平衡，对这些节律的分析是生物医学科学中的一个新兴领域。在脊椎动物的节段化过程中，极端的振荡支配着体节的形成，体节是脊椎的节段性原。在斑马鱼、小鼠和人类中，体细胞发育需要Notch信号，而Notch信号的干扰会导致脊椎畸形，这是一种称为脊柱肋骨发育不良的先天缺陷。依赖于Notchilla的Oscilla基因导致斑马鱼分割组织中的细胞经历Notch靶基因的重复表达和抑制周期。HER(裂解相关转录抑制因子的毛状/增强子)基因被认为在斑马鱼的分段时钟内形成一个负反馈环。目前的数据表明，不同的/低基因既有独特的功能，也有多余的功能。目的了解HER基因在斑马鱼生物钟中的功能多样性，并确定控制转录振荡的顺式序列。为了实现这些目标，我们将使用凝胶迁移率改变分析(EMSA)、免疫沉淀和转基因斑马鱼。目的二是开发对转基因的温度敏感控制，以便精确地调节表达水平和时间。这一策略解决了在动态信号网络和发育时间的背景下识别信号整合和基因功能的一般问题。我们的目标三是描述细胞运动和分段时钟之间的关系。使用时间流逝成像和CELT跟踪，我们将确定速度。不同rq9离子在尾芽中凯尔特人的方向和邻居关系。

Oscillations are common in biology, e.g. the circadian clock, cardiac pacemaker, cortical rhythms, and have been observed in cell signaling networks as a result of feedback loops. These cellular and physiological oscilla tions maintain homeostasis and analysis of these rhythms is an emerging area in biomedical science. During vertebrate segmentation, ultradian oscillations govern the formation of somites, the segmented anlagen of the vertebral column. In zebrafish, mice and humans, somitogenesis requires Notch signaling, perturbation of which leads to malformed vertebrae, a birth defect called spondylocostal dysostosis. The Notchdependent oscilla tions cause cells in the segmenting tissue of the zebrafish to undergo repeated cycles of expression and repression of Notch target genes. The her (hairy/enhancer of split related tranSCfiptional repressors) genes are thought to form a negative feedback loop within the zebrafish segmentation clock. Current data suggest thai the different /lergenes have both unique and redundant functions. Aim I is to understand the functional diversification of her genes within the zebrafish clock and to identify cis sequences that govern transcriptional oscillations. To achieve these aims, we will use electrophoretic mobility shift assays (EMSA), immunoprecipitation and transgenic zebrafish. Aim II is to develop a temperature-sensitive control of the transgenes in order to precisely tune the level and timing of expression. This strategy deals with the general problem of discerning signal integration and gene function within the context of dynamic signaling networks and developmental lime. We are Aim III is to characterize the relationship between cell movement and the segmentation clock. Using timelapse imaging and celt tracking, we will determine the velocity. direction and neighbor relationships of celts in different rQ9ions of the tail bud.