Molecular specification of the pre-placodal ectoderm

Sally A. Moody, ph . d .提案# IOS-0817902“胎盘前外胚层的分子规范。”脊椎动物胚胎的“外胚层”最初分为四个区域：表皮（皮肤）、神经板（中枢神经系统的前体）、神经嵴（周围神经系统的前体）和前placodal外胚层（头部几个感觉器官的前体）。特别是，胎盘前外胚层产生了嗅觉和听觉系统、眼睛的晶状体、头部的许多感觉神经元以及鱼类和两栖动物的侧线器官。尽管调控神经板、神经嵴和表皮形成的发育机制已被广泛研究，但对胎盘前外胚层的发育知之甚少。这一建议将阐明：1)诱导胎盘前外胚层形成的分子相互作用；2)在头部发育过程中建立并维持四个外胚层域之间的边界。虽然基因发育的这些早期步骤在突变小鼠的研究中被忽视了，也许是因为它们发生在很早的时候，啮齿动物的胚胎特别脆弱，但它们特别适合在爪蟾蛙身上进行研究，因为它们很容易进入早期发育阶段，而且有丰富的可用分子和胚胎学工具。拟议的研究将提供关于建立这一重要外胚层结构域的基因和组织相互作用的重要新知识，并有望阐明在脊椎动物中这些结构中发生的遗传和进化变化。就更广泛的影响而言，由于Xenopus系统允许人们在没有广泛的技术专业知识的情况下可视化和操纵基因表达，因此实验方法可以教授给高中，本科生和研究生，从而为有兴趣探索科学事业的学生提供出色的学习体验。

Sally A. Moody, Ph.D.Proposal# IOS-0817902"Molecular specification of the pre-placodal ectoderm."The "ectoderm" of the vertebrate embryo is initially patterned into four domains: epidermis (skin), neural plate (the precursor of the central nervous system), neural crest (a precursor of the peripheral nervous system) and pre-placodal ectoderm (the precursor of several sensory organs in the head). In particular, the pre-placodal ectoderm gives rise to the olfactory and auditory systems, the lens of the eye, numerous sensory neurons in the head and the lateral line organ in fish and amphibians. Although the developmental mechanisms that regulate the formation of the neural plate, neural crest and epidermis have been studied extensively, very little is known about the development of the pre-placodal ectoderm. This proposal will elucidate the molecular interactions that: 1) induce the formation of the pre-placodal ectoderm; and 2) establish and maintain the boundaries between the four ectodermal domains as the head develops. Although these early steps of placode development have been overlooked in mutant mouse studies, perhaps because they occur very early when rodent embryos are especially fragile, they are particularly amenable to study in Xenopus frogs because of easy access to the early developmental stages and wealth of available molecular and embryological tools. The proposed studies will provide important new knowledge about the genes and tissue interactions that establish this important ectodermal domain, and is expected to elucidate the genetic and evolutionary changes that have occurred in these structures across vertebrates. In terms of Broader Impacts, because the Xenopus system allows one to visualize and manipulate gene expression without extensive technical expertise, the experimental approaches can be taught to high school, undergraduate and graduate students and thereby provide an outstanding learning experience for students interested in exploring a career in science.