Environment-specific effects of new mutations on gene expression

 描述（由申请人提供）：基因型转化为表型的环境中的变异既可以通过可塑性诱导表型差异，也可以通过自然选择为不同的最优值过滤表型变异。因此，要理解可塑性的进化，就需要解开环境作为发育和选择的媒介的角色，这只有通过研究尚未受到选择的新突变的表型效应才有可能。在这里，我建议调查的影响，新的突变对基因表达水平的环境背景下，在芽殖酵母。利用高通量筛选分离影响基因表达的新突变，我将描述突变对基因表达的影响的分布和9个基因的不同环境中单个新突变的影响之间的相关程度。通过定点诱变，我将调查顺式调控突变对基因表达的影响，以确定通过破坏已知的调控基序可能跨环境的表达变化的广度，并测量其对生长的影响。通过研究这些新的调节突变对适应性的影响，我将描述基因表达可塑性选择的进化信号。

 DESCRIPTION (provided by applicant): Variation in the environment in which genotypes are translated into phenotypes can both induce phenotypic differences through plasticity and filter phenotypic variation for different optima via natural selection. Understanding the evolution of plasticity thus requires disentangling the role of environment as an agent of development and as an agent of selection, possible only through studying the phenotypic effects of new mutations not yet subject to selection. Here I propose to investigate the effects of new mutations on gene expression levels across environmental contexts in budding yeast. Taking advantage of a high throughput screen for isolating new mutations influencing gene expression, I will characterize the distribution of mutational effects on gene expression and the degree of correlation among the effects of individual new mutations across environments for nine genes. Through site-directed mutagenesis, I will investigate the effects of cis regulatory mutations on gene expression to identify the breadth of expression changes possible across environments through disruption of known regulatory motifs, and measure their consequences for growth. By examining the effects of these new regulatory mutations on fitness, I will characterize the evolutionary signal for selection on plasticity in gene expression.