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环境线索做出反应的能力。 这种可塑性被认为允许进化更快地发生，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使某些生物具有这种可塑性。 这个项目将研究一组基因，创造可塑性的线虫Pristionchus pacificus。 这种蠕虫有不同的嘴结构和行为取决于拥挤和食物的可用性。 这项研究将确定这些基因的功能以及它们如何相互作用，并将重建这些基因如何在没有发育可塑性的相关物种中进化。 研究结果将显示发育可塑性如何在个体基因水平上运作和变化。 此外，研究人员将培训本科生，研究生和博士后学生在生物学研究跨越遗传学，发育生物学和进化领域。 这项研究将加强印第安纳州大学建立的两个成功的科学推广计划：a）PI将在自己的研究项目中主持和指导代表性不足的少数民族高中学生，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，以改善国家生命科学标准的教学和学习。该项目将建立一个功能性遗传理解的发展如何应对不同的环境设置，特别是通过生产离散，可选的表型（即，多型性）。 研究的目的是双重的。首先，它将表征的遗传因素和途径，构成一个发育开关的模式线虫太平洋棱纹线虫多型，通过：（i）克隆和确定的空间表达的基因，作用下游的一个已知的多型开关基因（EUD-1），和;（ii）凭经验确定它们的产品之间的相互作用如何形成一个环境响应开关。 其次，研究这些因子是如何随着多效性调节的分化而发生变化或承担新的功能的。 具体而言，该研究将通过以下方式重建这些因子的进化历史：（i）推断序列进化模式并识别潜在的功能变体;（ii）在其他物种中使用反向遗传学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分歧，该研究项目将开创性地对发育可塑性-特别是多型性-如何响应环境输入以及其调节如何随进化时间而变化进行功能遗传分析。

"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.