Use of the Homeobox System to Elucidate Metazoan Sister-Group Relationships

巴斯博士和拉德尔博士提议启动一项研究计划 旨在解决后生动物门的问题。当前 后生动物生殖状态是相当不确定的， 形态学和分子学数据集支持相互矛盾的 假设他们认为对Antp类同源异型盒的研究 基因将被证明有能力解决这个问题 不确定性同源盒序列的极端保守性 以及它们独特的基因组组织模式 丰富的特征理想的更高层次的系统发育 分析.在这份提案中，他们将重新审视 环节动物和节肢动物之间的区别， 基因组多样性，组织和同源框序列， 甲壳类，螯肢类，蛛形纲，软体动物，爪类， 和环节动物结合不断增长的现有数据库， 在刺胞动物、线虫、单枝动物、棘皮动物和 脊索动物，这项工作拥有解决不现实的承诺， 不仅环节动物和节肢动物的关系， 光在内部和最speciose之间的关系 原口门和后口门。同源盒系统的使用 进行系统发育分析是特别引人注目的，因为 这些基因已被证明是 参与早期胚胎模式形成的调控网络 和细胞命运的规范。因此，正如我们对 发展的分子遗传学的增长，很可能是， 在这项研究的进展中产生的信息将 允许研究开发新颖性的起源。到 要实现这些目标，就需要 发育遗传学家和进化生物学家。

Drs. Buss and Ruddle propose to initiate a research program directed at the resolution of the metazoan phyla. The current state of metazoan phylogeny is one of considerable uncertainty, with morphological and molecular data sets supporting conflicting hypotheses. They suggest that examination of Antp-class homeobox genes will prove capable of resolving the principle uncertainties. The extreme conservation of sequence of homeoboxes and their distinctive pattern of genomic organization provide an abundance of characters ideal for higher level phylogenetic analysis. In this proposal, they will re-examine the relationship between annelids and arthropods by characterization of the genomic diversity, organization, and sequences of homeoboxes from crustaceans, chelicerates, arachnids, molluscs, onychophorans, and annelids. Combined with the growing existing database on homeoboxes in cnidarians, nematodes, uniramians, echinoderms and chordates, this work holds the realistic promise of resolving not only the annelid-arthropod relationship, but also of shedding light on the relationships within and between the most speciose protostome and deuterostome phyla. The use of the homeobox system for phylogenetic analysis is particularly compelling because these genes have proved to be central components of the regulatory networks involved in early embryonic pattern formation and specification of cell fate. Thus, as our understanding of the molecular genetics of development grows, it is likely that the information generated in the progress of this research will permit study of the origin of the developmental novelty. To accomplish these goals it will require the collaboration of developmental geneticists and evolutionary biologists.