GENETICS OF COAT COLOR VARIATION IN POCKET MICE

进化的一个中心目标是明确地将生态上重要的性状的基因型和表型联系起来。 这一直是一个难以捉摸的目标，因为大多数性状的遗传基础还没有得到很好的理解。 啮齿类动物的毛色变化是响应当地适应的表型变化的一个典型例子：在许多物种中，背部皮毛的颜色与动物生活的土壤颜色非常匹配。 家鼠毛色的遗传学研究已经产生了丰富的候选基因和突变效应数据库。 口袋小鼠（Chaetodipus intermedius）的皮毛颜色的显着表型变异和实验室小鼠中克隆的候选色素沉着位点的组合，提供了一个无与伦比的机会，调查自然界中的一个关键形态特征的遗传变异。 拟议的研究将（1）记录存在于浅色和深色基质上的小鼠的毛色变化，（2）筛选候选基因座以鉴定有助于观察到的表型差异的基因，（3）表征相关基因座的突变等位基因，（4）比较深色种群中的突变等位基因，以及（5）记录选择作用并估计突变的年龄。 这些研究将共同（1）确定有助于毛色变化的基因的数量和相对强度，（2）确定色素沉着的差异是否是由于基因的结构或调控区域的变化，以及（3）确定是否相同或不同的突变发生在深色种群中。

A central goal in evolution is to explicitly connect genotype and phenotype for traits that are ecologically important. This has been an elusive goal because the genetic basis of most traits is not well understood. Coat color variation in rodents is a classic example of phenotypic variation in response to local adaptation: in many species, dorsal pelage color closely matches the soil color on which the animals live. Research on the genetics of coat color in the house mouse has produced a rich database of candidate genes and mutant effects. The combination of striking phenotypic variation in coat-color in pocket mice (Chaetodipus intermedius) and candidate pigmentation loci cloned in the laboratory mouse presents an unparalleled opportunity to investigate the genetic variation underlying a key morphological trait in nature. The proposed research will (1) document coat color variation in mice existing on both light and dark substrate, (2) screen candidate loci to identify genes contributing to observed phenotypic differences, (3) characterize mutant alleles of the implicated loci, (4) compare mutant alleles across dark populations, and (5) document selection acting on and estimate the age of the mutations. Together these studies will (1) identify the number and relative strength of genes contributing to coat color variation, (2) determine whether differences in pigmentation are due to changes in structural or regulatory regions of genes, and (3) determine if the same or different mutations occurred across dark populations.