Regulation of Vascular Development in Hydrozoa

血管系统对大多数大型动物的生长和发育都是必不可少的。 厘米大小，因为扩散不充分。Cnidaria的成员，是最早的动物之一 门，展示原始的血管系统。殖民地蛇类由相互连接的息肉组成 一种共同的维管系统，整合了整个群体的行为。息肉通过以下方式收集和分配食物 通过胃血管系统输送。血管运输对食物的可获得性、氧气 紧张和其他环境因素，以及血管结构。菌落形态与 胃血管运输，因此，菌落形态的可塑性是相当大的，并且可以适应。 拟议项目的目标是确定调控血管发育的机制及其 水生动物的可塑性代表了后生动物共有的原始特征。这一目标将通过以下方式实现 检验以下假设：(1)水生动物菌落形态对氧分压(PO2)的反应是可塑性的， 海水黏度的处理改变了匍匐茎内胚层细胞的剪切力。(2)差饷 匍匐茎内胚层细胞的息肉形成、匍匐茎分枝和有丝分裂不同于长度和长度。 它们所栖息的匍匐茎的建筑。(3)管腔内皮细胞有丝分裂率 对低氧和血管剪切力的反应，使匍匐茎增加。(4)缺氧诱导因子-1α、血管内皮生长因子、 而基质金属蛋白酶基因同源物在低氧和血管切应力的反应中增加 因此，它们与调节匍匐茎生长和分枝的作用是一致的。如果血管发育 水生动物和脊椎动物的调控机制是相同的，长期目标是发展 集群水生动物作为脊椎动物血管研究的替代和补充模型 功能及其病理。 事实上，这项研究与公共健康的相关性在于水生动物胃血管的可能性。 作为研究人类血管功能的模型的系统，因为进化保守 由生理反应触发的发育信号通路。利用的实际效益 它们作为模型包括活体实验、低成本、克隆复制和很少的伦理约束。

Vascular systems are essential for the growth and development of most animals larger than a few centimeters in size because diffusion is inadequate. Members of the Cnidaria, one of the earliest animal phyla, exhibit primitive vascular systems. Colonial cnidarians consist of polyps connected to one another by a common vascular system that integrates colony-wide behavior. Polyps gather and distribute food by pumping it through the gastrovascular system. Vascular transport is sensitive to food availability, oxygen tension and other environmental factors, and vascular architecture. Colony form is inextricably linked to gastrovascular transport and, consequently, plasticity of colony form is considerable and can be adaptive. The goal of the proposed project is to determine if mechanisms regulating vascular development and its plasticity in hydrozoans represent shared primitive characters of metazoans. This objective will be met by testing the following hypotheses: (1) Hydrozoan colony form is plastic in response to oxygen tension (pO2), and manipulations of seawater viscosity that alter shear stress on endodermal cells of stolons. (2) Rates of polyp formation, stolon branching and mitosis of stolon endodermal cells differ with the length and architecture of the stolon on which they reside. (3) Mitotic rates of endodermal cells lining the lumen of stolons increase in response to hypoxia and vascular shear stress. (4) Expression of HIF-1 alpha, VEGF, and matrix metalloproteinase gene homologues increase in response to hypoxia and vascular shear stress and are, therefore, consistent with roles regulating growth and branching of stolons. If vascular development of hydrozoans and vertebrates are regulated by the same mechanisms, the long-term goal is to develop colonial hydrozoans as alternative and complementary models to those of vertebrates for studies of vascular function and its pathologies. Indeed, the relevance of this research to public health lies in the potential for hydrozoan gastrovascular systems to serve as models for studies of human vascular function because of evolutionary conservation of developmental signaling pathways triggered by physiological responses. The practical benefits of utilizing them as models include in vivo experimentation, low cost, clonal replication, and few ethical constraints.