Genetic Regulation and Divergence of Developmental Plasticity in Pristionchus nematodes

“发育可塑性”是指具有相同基因的生物对来自环境的提示做出反应的能力。这种可塑性被认为使进化发生得更快，因为它允许一个物种具有多种特征。我们还不知道有多少基因可以让某些生物具有这种可塑性。这个项目将研究一组创造太平洋线虫可塑性的基因。这种蠕虫有不同的嘴结构和行为，这取决于拥挤和食物的可获得性。这项研究将确定这些基因的功能以及它们如何相互作用，并将重建这些基因是如何在没有发育可塑性的相关物种中进化的。研究结果将显示发育可塑性是如何在单个基因水平上运作和变化的。此外，研究人员还将培训本科生、研究生和博士后，从事跨越遗传学、发育生物学和进化论领域的生物学研究。这项研究将加强印第安纳大学建立的两个成功的科学推广项目：a)PI将在他们自己的研究项目中接待和指导未被充分代表的少数族裔高中生，收集数据，并在年度海报会议上展示研究结果；b)PI将帮助高中教师开发和实施项目、实验和活动作为课堂资源，以改进州生命科学标准的教和学。该项目将建立对发育如何响应不同环境设置的功能遗传学理解，特别是通过产生离散的、可选的表型(即多面体)。这项研究的目的有两个。首先，它将通过以下方法来表征构成模式线虫多物性发育开关的遗传因素和途径：(I)克隆并确定作用于已知多物性开关基因(eud-1)下游的基因的空间表达；以及(Ii)经验地确定它们的产物之间的相互作用如何形成环境响应开关。其次，研究将确定这些因素如何随着多面性调节的差异而改变或承担新的功能。具体地说，这项研究将通过以下方式重建这些因子的进化史：(I)推断序列进化的模式并识别潜在的功能变异；以及(Ii)在其他物种中使用反向遗传学来对这些因子进行比较功能测试。通过分析形成发育开关的遗传途径及其组成部分的进化差异，这项研究项目将开创一种功能遗传学分析，研究发育可塑性--具体地说，多种性--如何对环境输入做出反应，以及其调控如何随着进化时间的推移而变化。

"Developmental plasticity" is the ability of creatures with identical genes to vary in response to cues from the environment. This plasticity is thought to allow evolution to occur faster because it allows a species to have multiple traits. We don't yet know of many genes that allow some creatures to have this plasticity. This project will study a set of genes that create plasticity in the nematode worm Pristionchus pacificus. This worm has different mouth structures and behaviors depending on crowding and availability of food. The research will determine the function of these genes and how they interact, and it will reconstruct how these genes have evolved in related species that don't have developmental plasticity. The results of the research will show how developmental plasticity operates and changes at the level of individual genes. In addition, the investigators will train undergraduate, graduate, and postdoctoral students in biological research spanning the fields of genetics, developmental biology, and evolution. The research will augment two successful science outreach programs established at Indiana University: a) the PI will host and mentor underrepresented minority high-school students in their own research project, collect data, and present findings at an annual poster conference; b), the PI will help high-school teachers to develop and implement projects, experiments, and activities as classroom resources to improve the teaching and learning of state life science standards.This project will build a functional genetic understanding of how development responds to diverse environmental settings, specifically through the production of discrete, alternative phenotypes (i.e., polyphenism). The objectives of the research are twofold. First, it will characterize the genetic factors and pathway that constitute a developmental switch for a polyphenism in the model nematode Pristionchus pacificus, by means of: (i) cloning and determining the spatial expression of genes that act downstream of a known polyphenism switch gene (eud-1), and; (ii) empirically determining how the interactions between their products form an environmentally responsive switch. Second, the research will determine how these factors change or assume new functions with the divergence of polyphenism regulation. Specifically, the research will reconstruct the evolutionary history of these factors via: (i) inferring patterns of sequence evolution and identifying potential functional variants, and; (ii) using reverse genetics in other species to perform comparative functional tests of those factors. Through analysis of a genetic pathway forming a developmental switch and the evolutionary divergence of its components, this research project will pioneer a functional genetic analysis of how developmental plasticity - specifically, a polyphenism - responds to environmental inputs, and how its regulation changes over evolutionary time.