Evolution of Axial Patterning

轴向图案的演变

• 批准号: 9904757
• 负责人: Hans Bode
• 金额: $ 27万
• 依托单位: University of California-Irvine
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-09-01 至 2002-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9904757&HistoricalAwards=false
• 关键词: Evolution; Axial; Patterning

Accumulating evidence indicates is that a common set of regulatory genes involved in a common, or related, set of mechanisms underlie many of the developmental processes of the metazoans studied so far. How early did these genes arise during metazoan evolution and to what extent has their function been conserved? A useful approach to these questions is to study such genes in a cnidarian, the first group of animals to have a defined body plan. Among the cnidaria, hydra is particularly useful as the developmental processes are extensively understood. The overall aim of the proposed work is to determine if the genes and mechanisms underlying axis formation and axial patterning in hydra are similar to those found vertebrates and arthropods. The four detailed aims are the following.In hydra, axis formation and axial patterning can be studied during the process of bud formation, the animal's asexual form of reproduction. Two of the aims focus on clarifying aspects of bud formation. [1] Of the three cell lineages in hydra, the two epithelial lineages [ectoderm and endoderm] play an obvious role. A possible role of the interstitial cell lineage will be investigated by manipulations that alter or eliminate this lineage. [2] A number of homologues of axial patterning genes found in vertebrates and Drosphila have been isolated from hydra and show to be expressed during bud formation. More direct evidence of their particular roles will be investigated by introducing anti-sense oligonucleotides against such genes into budding tissue.The other two aims focus on the isolation of new genes involved in axial patterning in hydra. One approach will be to look for homologues of genes involved in dorsal-ventral patterning, which is in part, highly conserved among vertebrates and Drosophila. The other involves using the induction of a 2nd axis in frog embryos to identify hydra genes involved in axial patterning. Any genes isolated with either procedure will be examined for their role in axial patterning in hydra by examining their expression patterns in a variety of developmental situations as well as using the anti-sense approach to gain more direct information.The results should extend the understanding of the evolution of axis formation as well as how animals with a single axis evolved into animals with more than one axis.

越来越多的证据表明，迄今为止研究的后生动物的许多发育过程都涉及一组共同的调控基因，这些基因参与一组共同的或相关的机制。 这些基因在后生动物进化过程中出现的时间有多早？它们的功能在多大程度上被保留？ 解决这些问题的一个有用方法是研究刺胞动物的此类基因，刺胞动物是第一批具有明确身体计划的动物。 在刺胞动物中，水螅特别有用，因为其发育过程已被广泛了解。 这项工作的总体目标是确定水螅轴形成和轴模式的基因和机制是否与脊椎动物和节肢动物相似。 四个详细目标如下。 在水螅中，可以在芽形成（动物的无性繁殖形式）过程中研究轴的形成和轴图案。 其中两个目标侧重于澄清芽形成的各个方面。 [1] 在水螅的三种细胞谱系中，两种上皮谱系[外胚层和内胚层]发挥着明显的作用。 将通过改变或消除该谱系的操作来研究间质细胞谱系的可能作用。 [2] 在脊椎动物和果蝇中发现的许多轴向模式基因的同源物已从水螅中分离出来，并显示在芽形成过程中表达。 通过将针对这些基因的反义寡核苷酸引入出芽组织，将研究它们特定作用的更直接证据。另外两个目标集中于分离参与水螅轴向模式的新基因。 一种方法是寻找与背腹模式相关的基因的同源物，该基因在脊椎动物和果蝇中部分高度保守。 另一种方法涉及利用青蛙胚胎中第二轴的诱导来识别参与轴向模式的水螅基因。 通过任一程序分离的任何基因都将通过检查其在各种发育情况下的表达模式以及使用反义方法获得更直接的信息来检查它们在水螅轴向模式中的作用。结果应该扩展对轴形成进化以及单轴动物如何进化为多轴动物的理解。