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的机制的了解存在着显著的差距。我的长期目标是深入了解幼虫发育和变态背后的信号体系结构，特别强调棘球类(海胆和沙鱼)中的甲状腺激素(TH)信号。虽然这些激素通常被认为是典型的脊椎动物激素，但我的初步数据强烈表明，它们在棘突幼虫的生活史中发挥了作用。此外，虽然发育中的信号分子通常被认为是严格内源产生的，但我的研究提供了海洋环境中THs有内部来源和外部来源的证据。因此，在本节目中，我将在海洋幼虫生活史及其进化的背景下，评估TH的外源和内源来源的作用。在这5年的授权期内，我的具体目标是：目标1：确认棘球藻类幼虫和浮游植物中TH相关化合物的存在和准确鉴定。目的2：寻找紫海胆TH信号和合成相关基因。目的3：比较两种同属沙棘TH的合成机制。这项研究将提供有关棘球幼虫发育和变态过程中TH信号的新数据。更广泛地说，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。这一研究计划的发现，特别是拟议项目的发现，将阐明1)变性生活史调节机制的同质性(即趋同、平行和逆转)的程度，以及2)这些信号系统如何通过进化被修改，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和现代个体发育、细胞和基因组方法之间的差距，该计划将展示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.