Iodine & tyroid hormone signaling in echinoid larvae

在许多海洋无脊椎动物门中，我们对幼虫发育和变态机制的认识存在重大差距。我的长期目标是深入了解幼虫发育和变态的信号结构，特别强调海胆（海胆和沙元）中的甲状腺激素（TH）信号。虽然TH通常被视为经典的脊椎动物激素，我的初步数据强烈建议在海胆幼虫的生活史的功能。此外，虽然发育信号分子通常被认为是严格内源性产生的，但我的研究提供了证据，证明海洋环境中的TH既有内部来源，也有外部来源。因此，在这个程序中，我将评估的作用，外源性和内源性来源的TH在海洋幼虫的生活史和它们的进化。我在这5年的资助期内的具体目标是：目标1：确认海胆幼虫和浮游植物中TH相关化合物的存在和准确身份。目的2：鉴定海胆TH信号转导和合成基因。紫色的目的3：比较两种沙元TH合成的机制。本研究将为海胆幼体发育和变态过程中TH信号的研究提供新的数据。更一般地说，它将扩大我们对无脊椎动物门中激素信号系统的理解，并阐明它们在生活史进化中的作用。 这项研究计划的结果，特别是拟议项目的结果将阐明1）在变质生活史调节机制中的同质性（即收敛，平行和逆转）的程度，以及2）这些信号系统如何通过进化进行修改，导致这些群体中生活史模式的广泛多样性。总之，通过弥合经典幼虫生活史与现代个体发生学、细胞学和基因组学方法之间的差距，该计划将发挥多学科生物学研究的潜力，为动物发育、进化和生态学提供新的见解。

Significant gaps exist in our knowledge on mechanisms underlying larval development and metamorphosis, in many marine invertebrate phyla. My long term objective is to gain insights into the signaling architecture underlying larval development and metamorphosis with specific emphasis on thyroid hormone (TH) signaling in echinoids (sea urchins and sand dollars). Although THs are generally viewed as classic vertebrate hormones, my preliminary data strongly suggests a function in echinoid larval life histories. Furthermore, while developmental signaling molecules are generally considered to be strictly endogenously produced, my research provides evidence that THs in the marine environment have both internal and external sources. In this program I will therefore evaluate the role of both, exogenous and endogenous sources of THs in the context of marine larval life histories and their evolution. My specific aims for this 5 year granting period are to: Aim 1: Confirm presence and precise identity of TH related compounds in echinoid larvae and phytoplankton. Aim 2: Identify putative TH signaling and synthesis genes in the sea urchin S. purpuratus. Aim 3: Compare mechanisms of TH synthesis in two congeneric sand dollar species. This research will produce novel data on TH signaling in echinoid larval development and metamorphosis. More generally, it will expand our understanding of hormonal signaling systems in invertebrate phyla and elucidate their role in life history evolution. Findings from this research program and specifically from the proposed project will elucidate 1) the extent of homoplasy (i.e. convergence, parallelism and reversal) in the mechanisms underlying the regulation of metamorphic life histories and 2) how these signaling systems may have been modified through evolution, leading to the extensive diversity of life history modes in these groups. In sum, by bridging the gap between classical larval life history and modern ontogenetic, cellular and genomic approaches, this program will exemplify the potential of multidisciplinary biological research to provide novel insights into animal development, evolution and ecology.