Tissue-specific and < i > cis < /i > -regulatory changes underlie parallel, adaptive gene expression evolution in house mice

by Sylvia M. Durkin, Mallory A. Ballinger, Michael W. Nachman Changes in gene regulation have long been appreciated as a driving force of adaptive evolution, however the relative contributions ofcis- andtrans-acting changes to gene regulation over short evolutionary timescales remain unclear. Instances of recent, parallel phenotypic evolution provide an opportunity to assess whether parallel patterns are seen at the level of gene expression, and to assess the relative contribution ofcis- andtrans- changes to gene regulation in the early stages of divergence. Here, we studied gene expression in liver and brown adipose tissue in two wild-derived strains of house mice that independently adapted to cold, northern environments, and we compared them to a strain of house mice from a warm, tropical environment. To investigate gene regulatory evolution, we studied expression in parents and allele-specific expression in F1 hybrids of crosses between warm-adapted and cold-adapted strains. First, we found that the different cold-adapted mice showed both unique and shared changes in expression, but that the proportion of shared changes (i.e. parallelism) was greater than expected by chance. Second, we discovered that expression evolution occurred largely at tissue-specific andcis-regulated genes, and that these genes were over-represented in parallel cases of evolution. Finally, we integrated the expression data with scans for selection in natural populations and found substantial parall...
Source: PLoS Genetics - Category: Genetics & Stem Cells Authors: Source Type: research