Evolutionary Genetics of Animal Development

项目总结 基因在生物学中扮演着两种不同的角色，通过发育过程形成表型 在个体内，并通过孟德尔遗传在世代之间传递特征。进化论 发育遗传学家在这些角色的交叉点上工作，询问这些机制是如何运作的 个体内影响种群表型变异的起源、维持和命运。 多效性、显性、上位性、多基因和连锁是统一发展的一些现象 和种群遗传学。另一类现象--早期胚胎发育--也弥合了这一点 分裂，涉及来自胚胎自身合子基因组的分子和细胞贡献，但也来自 卵子的物质，是其母亲基因组的产物。这种由两个基因组进行的双重调节产生了 早期发育的独特传播遗传学特性，改变预测的特性 变异和分歧的模式。 为了更好地了解母体和受精卵的遗传效应及其相互作用如何形成变异和 发展的进化，这个项目的目标是表征人类的遗传结构 多个实验模型系统中的胚胎发生，每个系统都有独特的互补特征。 其中一项研究集中在线虫上，这是一种长期存在的实验模型 发育遗传学。建立在实验室用于定量遗传分析的广泛资源的基础上 ，该项目将使用受控的实验杂交来揭示基因变异，这些变异要么作用于 母亲的基因组或其后代的基因组影响发育基因的表达。该项目将使用 线虫的两个实验面板，一个最大化检测能力，另一个最大化映射 决议。为了解决交配系统在母体-受精卵共同进化中的作用的问题，该项目 还将使用贝氏针茅的实验板，这是一种近缘物种，在 与秀丽线虫的自花授精形成鲜明对比。 第二条线的研究重点是胚胎发育的变异，一种环节动物模型系统，Streblospio 贝内迪克蒂。本种的独特之处在于表现为可遗传变异的直接和间接发展， 替代模式代表了适应不同环境条件的策略。这个系统 为线虫胚胎发生的稳定选择提供了一个定向选择的对应物 经历。对本氏链霉菌大型家系中胚胎基因表达的测量将有助于遗传 剖析母体和受精卵对发育的贡献，并检验母体受精卵的作用 推动或阻止适应性进化的遗传交互作用。

PROJECT SUMMARY Genes play two different roles in biology, giving shape to phenotypes through developmental processes within individuals, and transmitting traits across generations through Mendelian inheritance. Evolutionary developmental geneticists work at the intersection of these roles, asking how the mechanisms that operate within individuals influence the origin, maintenance, and fate of phenotypic variation in populations. Pleiotropy, dominance, epistasis, polygeny, and linkage are some of the phenomena that unite developmental and population genetics. One further class of phenomenon – early embryonic development – also bridges this divide, involving molecular and cellular contributions from the embryo's own zygotic genome but also from the substance of the egg, a product of its mother's genome. This dual regulation by two genomes creates distinctive transmission genetics properties for early development, properties that alter predictions about patterns of variation and divergence. To better understand how maternal and zygotic genetic effects and their interactions shape variation and evolution of development, this project sets as its goal the characterization of genetic architectures of embryogenesis in multiple experimental model systems, each with unique complementary features. One line of research focuses on Caenorhabditis nematodes, a longstanding experimental model for developmental genetics. Building on the lab's extensive resources for quantitative genetic analysis in these animals, the project will use controlled experimental crosses to reveal genetic variants that act either in the mother's genome or in that of her offspring to influence developmental gene expression. The project will use two experimental panels of C. elegans, one that maximizes detection power and one that maximizes mapping resolution. To address questions about the role of mating system in maternal-zygotic coevolution, the project will also use an experimental panel of C. becei, a closely related species that exhibits obligate outcrossing in contrast to the self-fertilization that characterizes C. elegans. A second line of research focuses on variation in embryonic development an annelid model system, Streblospio benedicti. This species is unique in exhibiting both direct and indirect development as heritable variation, with the alternative modes representing adaptive strategies to different environmental conditions. This system provides a directional selection counterpart to the stabilizing selection that Caenorhabditis embryogenesis experiences. Measurements of embryonic gene expression in a large S. benedicti pedigree will facilitate genetic dissection of both maternal and zygotic contributions to development and tests of the role of maternal-zygotic genetic interactions in driving or preventing adaptive evolution.