Cell division, apoptosis during zebrafish hepatogenesis

描述（由申请人提供）： 了解细胞分裂和细胞死亡对斑马鱼肝发生的贡献是本研究的目的。这将是通过插入诱变筛选产生的斑马鱼突变体进行系统筛选的首批努力之一，该筛选在霍普金斯实验室已接近完成。这项筛选已经确定了500多个基因，当突变时，会破坏早期发育。 这些基因中的相当一部分已被鉴定为在细胞分裂或凋亡中起作用或者是新基因。这些突变体将为揭示在肝发生过程中调节细胞生死平衡的基因以及为新的必需基因分配功能提供肥沃的土壤。我的第一个目标是提供一个详细的描述斑马鱼肝脏发育，包括描绘的模式，细胞分裂和死亡在肝发生。其次，我将充分描述pescadillo（per）突变体的特征，除了其他缺陷外，它只发育成一个不成熟的肝脏，我将检验pes肝细胞不能分裂导致肝源性衰竭的假设。第三，通过研究这些突变体发育过程中肝脏的大小和肝脏特异性基因表达的模式，我将询问霍普金斯筛选发现的参与细胞分裂或凋亡的基因是否有助于肝发生。最后，我将筛选所有新的基因突变体，以确定那些在肝脏大小的缺陷。将对鉴定的突变体进行进一步分析，包括突变体的描述、野生型发育过程中基因的表达模式和肝发生的全面研究，以便开始理解这些新的必需基因中的一些的功能。

DESCRIPTION (provided by applicant): Understanding the contributions of cell division and cell death to zebrafish hepatogenesis is the aim of this study. It will be among the first efforts to systematically screen through the zebrafish mutants generated by an insertional mutagenesis screen that is near completion in the Hopkins laboratory. This screen has identified over 500 genes which, when mutated, disrupts early development. A significant portion of these genes have been identified as having a role in either cell division or apoptosis or are novel gene. These mutants will provide fertile ground for both uncovering genes that regulate the balance between cellular life and death during hepatogenesis as well as assigning a function to novel, essential genes. My first aim is to provide a detailed description of zebrafish liver development, including delineation of the pattern of cell division and death during hepatogenesis. Second, I will fully characterize the pescadillo (per) mutant which, among other defects, only develops only a rudimentary liver and I will test the hypothesis that hepatogenic failure in pes results from an inability for pes hepatocytes to divide. Third, I will ask whether any of the genes involved in cell division or in apoptosis uncovered by the Hopkins screen contribute to hepatogenesis by investigating the size of the liver and the pattern of liver-specific gene expression during development in these mutants. Finally, I will screen through all of the novel gene mutants to identify those with a defect in liver size. The mutants identified will be subject to further analysis including a description of the mutant, the expression pattern of the gene during wild-type development and a full investigation hepatogenesis so that the function of some of these novel, essential genes may begin to be understood.