Evolution and Development of Vertebrate Hox14 Genes

这项研究将调查一组迄今未知的类似脊椎动物HOX基因，Hox14。编码Hoxa14和Hoxd14的基因最近分别在腔棘鱼和棘鳃中被发现，初步数据表明这些基因具有生物功能。这些发现提出了许多与这些基因的进化和发展密切相关的问题。将实现四个具体目标。前两项分别是克隆七鳃鳗和肺鱼的Hox14基因并对其进行基因组特征分析。已经设计了一些策略，以利用该实验室在脊椎动物HOX基因的基因组分离和表征方面的专业知识。第三个目标是研究和比较Hox14基因在溜冰鱼和七鳃鳗中的表达模式。为了评估Hox14在胚胎发育中的直接作用，将在七鳃鳗中进行功能实验。第四个目标将描述和研究Hoxa14和Hoxd14编码序列附近假定的顺式调控元件的发育作用。其中一个这样的元素已经被证明参与了三个替代系统中明确和一致的体内表型，从而加强了这一目标的理论基础。这四个具体目标是独立的，不是相互依存的。这项研究的首要目标是了解Hox14基因在脊椎动物进化和发育中可能扮演的角色。在脊椎动物中发现Hox14基因是意想不到的，它们在大约4亿年前分化的不同脊椎动物谱系中的维持表明，它们可能在发育中发挥了关键作用。这项研究的“广泛影响”通过两种方式衡量：(1)通过采用高度跨学科的方法解决问题，包括基因组学、进化生物学、发育生物学和自然历史；(2)通过提供丰富的研究和教育资源和机会。研究资源包括公开可用的基因库和其他试剂。培训机会包括为代表不足的少数族裔的本科生提供培训机会。

This research will investigate a paralogous group of hitherto unknown vertebrate Hox genes, Hox14. Genes encoding Hoxa14 and Hoxd14 were recently discovered in the coelacanth and elasmobranchs, respectively, and preliminary data suggest that these genes are biologically functional. The findings raise numerous questions germane to the evolution and development of these genes. Four Specific Aims will be pursued. The first two are to clone and genomically-characterize Hox14 genes from the lamprey and lungfish, respectively. Strategies have been designed to take advantage of the laboratory's expertise in the genomic isolation and characterization of vertebrate Hox genes. The third Aim will examine and compare expression patterns of Hox14 genes in both the skate and the lamprey. Functional experiments will be undertaken in the lamprey in order to assess the direct role of Hox14 in embryological development. The fourth Aim will delineate and examine the developmental role of putative cis regulatory elements in the vicinity of the Hoxa14 and Hoxd14 coding sequences. One such element has been shown to be involved in a clear and consistent phenotype in vivo in three surrogate systems, thus strengthening the rationale for this Aim. The four Specific Aims are independent and not contingent on one another. The overarching goal of this research is to understand the role that Hox14 genes may have played in vertebrate evolution and development. The discovery of Hox14 genes in vertebrates was unexpected and their maintenance in distinct vertebrate lineages that diverged some 400 million years ago suggests that they may have played a key developmental role. The "broad impact" of this research is measured in two ways: (1) through employment of highly interdisciplinary approaches to problem solving, including genomics, evolutionary biology, developmental biology and natural history; and (2) by providing a wealth of research and educational resources and opportunities. The research resources include publicly available gene libraries and other reagents. The training opportunities include traineeships for undergraduates of underrepresented minorities.