DISSERTATION RESEARCH: The Structure of Heritable Variation in Developmental Gene Expression in the Purple Urchin

基因表达的可遗传变异是发育进化的原材料，但对这种变异在自然界的分布几乎一无所知。本提案概述了一项计划，以估计发育生物学模型系统紫海胆自然种群中发育基因表达的遗传变异结构。通过使用定量遗传技术，基因产物丰度的遗传变异模式将在胚胎发育的四个阶段的每一个阶段估计120个基因。结果估计将有助于回答几个悬而未决的问题：有多少遗传变异存在于早期发育的基因表达？遗传变异和共变的时间进程是怎样的？母系效应如何影响基因表达的变异？最后，调控基因相互作用的网络如何影响发育变异的结构，从而影响发育进化的可能性？本研究将有助于进化生物学和发育生物学的综合，为研究海胆的遗传变异提供新的途径，并将数量遗传学引入海胆的研究中。此外，更深入地了解发育基因表达性状之间的遗传相关性模式，可以应用于动物育种和医学关联研究。

Heritable variation in gene expression is raw material for the evolution of development, yet almost nothing is known about the distribution of such variation in nature. This proposal outlines a plan to estimate the structure of heritable variation in developmental gene expression in a natural population of purple sea urchins, a model system for developmental biology. Through the use of quantitative genetic techniques, the pattern of heritable variation in the abundance of gene products will be estimated for 120 genes at each of four stages in embryonic development. The resulting estimates will help answer several outstanding questions: How much heritable variation exists for early developmental gene expression? What is the timecourse of genetic variation and covariation? How do maternal effects influence variation in gene expression? Finally, how do networks of regulatory gene interactions influence the architecture of developmental variation, and hence the possibilities for developmental evolution? This research will contribute to the synthesis of evolutionary and developmental biology, validate a new approach to studying heritable trait variation, and introduce quantitative genetics into sea urchin research. In addition, a deeper understanding of the patterns of genetic correlations among developmental gene expression traits could have applications to animal breeding and medical association studies.