title: Repression and loss of gene expression outpaces activation and gain in recently duplicated fly genes.
abstract: Evolutionists widely acknowledge that regulatory genetic changes are of paramount importance for morphological and genomic evolution. Nevertheless, mechanistic complexity and a paucity of data from nonmodel organisms have prevented testing and quantifying universal hypotheses about the macroevolution of gene regulatory mechanisms. Here, we use a phylogenetic approach to provide a quantitative demonstration of a previously hypothesized trend, whereby the evolutionary rate of repression or loss of gene expression regions is significantly higher than the rate of activation or gain. Such a trend is expected based on case studies in regulatory evolution and under models of molecular evolution where duplicated genes lose duplicated expression patterns in a complementary fashion. The trend is important because repression of gene expression is a hypothesized mechanism for the origin of evolutionarily novel morphologies through specialization.
authors.affiliation: Ecology Evolution and Marine Biology, University of California, Santa Barbara, CA 93106, USA. oakley@lifesci.ucsb.edu
authors.forename: Todd H
authors.initials: TH
authors.lastname: Oakley
authors.forename: Bjørn
authors.initials: B
authors.lastname: Ostman
authors.forename: Asa C V
authors.initials: AC
authors.lastname: Wilson
mesh_terms: D000818:Animals; D004331:Drosophila melanogaster / Q000235:genetics; D019143:Evolution, Molecular; D020440:Gene Duplication; D015870:Gene Expression; D016678:Genome; D016013:Likelihood Functions; D008390:Markov Chains; D008957:Models, Genetic; D010802:Phylogeny