Evolution of Axial Patterning - Functional Approaches

描述（由申请人提供）： 本研究的目的是探讨多细胞动物发育过程中轴向区域化关键调控基因的功能。这一目标福尔斯属于解决后生动物分子模式化机制的基本问题的长期综合目标。在这项研究中，我们将使用功能性遗传分析，以确定的轴向模式在刺胞动物的Hox/ParaHox基因的作用。HoxlParaHox基因在三胚层动物的前后模式中的保守功能定义了双侧“动物型”。这些基因是否在刺胞动物中发挥类似的作用还有待确定。有几个具体目标。 在这项研究中，首先，后ParaHox基因将从Nematostella vectensis（刺胞动物门：珊瑚虫）分离和其表达模式的特点。接下来，将在N. vectensis使用两个互补的功能测定，异位基因表达和基因沉默。最后，刺胞动物的Hox/ParaHox基因的功能在再生过程中将被检查，以阐明潜在的同源性之间的机械事件在个体发育和再生。确定Hox/ParaHox基因在刺胞动物中的功能将使我们能够建立刺胞动物和双侧刺胞动物之间的轴向同源性。这些结果将揭示Hox和ParaHox基因在早期后生动物历史中的祖先作用，并将为复杂身体计划的进化提供有价值的见解。

DESCRIPTION (provided by applicant): The objective of this research is to investigate functions of key regulatory genes in axial regionalization during development of multicellular animals. This objective falls within the long-range comprehensive goal of addressing fundamental questions of molecular patterning mechanisms in metazoans. In this study, we will use functional genetic assays to determine the roles of the Hox/ParaHox genes in axial patterning in cnidarians. The conserved function of HoxlParaHox genes in anterioposterior patterning of triploblastic animals defines the bilaterian 'zootype'. Whether these genes perform comparable roles in cnidarians remains to be determined. There are several specific aims. In this proposed study. First, a posterior ParaHox gene will be isolated from Nematostella vectensis (Cnidaria: Anthozoa) and its expression pattern characterized. Next, the function of cnidarian Hox/ParaHox genes during development will be examined in N. vectensis using two complementary functional assays, ectopic gene expression and gene silencing. Finally, the function of cnidarian Hox/ParaHox genes during the process of regeneration will be examined to elucidate potential homology between the mechanistic events in ontogeny and regeneration. Determining Hox/ParaHox gene function in cnidarians will allow us to establish axial homologies between cnidarians and bilaterians. These results will reveal the ancestral roles of Hox and ParaHox genes in early metazoan history and will provide valuable insight to the evolution of complex body plans.