title: Patterns of Gene Conversion in Duplicated Yeast Histones Suggest Strong Selection on a Coadapted Macromolecular Complex.
abstract: We find evidence for interlocus gene conversion in five duplicated histone genes from six yeast species. The sequences of these duplicated genes, surviving from the ancient genome duplication, show phylogenetic patterns inconsistent with the well-resolved orthology relationships inferred from a likelihood model of gene loss after the genome duplication. Instead, these paralogous genes are more closely related to each other than any is to its nearest ortholog. In addition to simulations supporting gene conversion, we also present evidence for elevated rates of radical amino acid substitutions along the branches implicated in the conversion events. As these patterns are similar to those seen in ribosomal proteins that have undergone gene conversion, we speculate that in cases where duplicated genes code for proteins that are a part of tightly interacting complexes, selection may favor the fixation of gene conversion events in order to maintain high protein identities between duplicated copies.
authors.affiliation: Division of Animal Sciences, University of Missouri, Columbia Present address: Genetics Graduate Program, Texas A&M University, College Station, TX.
authors.forename: Kathy
authors.initials: K
authors.lastname: Scienski
authors.affiliation: Department of Genetics, Washington University Center for Genome Sciences and Systems Biology, Washington University conantg@missouri.edu jfay@genetics.wustl.edu.
authors.forename: Justin C
authors.initials: JC
authors.lastname: Fay
authors.affiliation: Division of Animal Sciences, University of Missouri, Columbia Informatics Institute, University of Missouri, Columbia conantg@missouri.edu jfay@genetics.wustl.edu.
authors.forename: Gavin C
authors.initials: GC
authors.lastname: Conant
mesh_terms: D019143:Evolution, Molecular; D005785:Gene Conversion; D020440:Gene Duplication; D006657:Histones / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics*; D012641:Selection, Genetic
chemical_list: D006657:Histones; D029701:Saccharomyces cerevisiae Proteins
keywords: gene conversion; genome duplication; histones