title: Evolution of H3K27me3-marked chromatin is linked to gene expression evolution and to patterns of gene duplication and diversification.
abstract: Histone modifications are critical for the regulation of gene expression, cell type specification, and differentiation. However, evolutionary patterns of key modifications that regulate gene expression in differentiating organisms have not been examined. Here we mapped the genomic locations of the repressive mark histone 3 lysine 27 trimethylation (H3K27me3) in four species of Drosophila, and compared these patterns to those in C. elegans. We found that patterns of H3K27me3 are highly conserved across species, but conservation is substantially weaker among duplicated genes. We further discovered that retropositions are associated with greater evolutionary changes in H3K27me3 and gene expression than tandem duplications, indicating that local chromatin constraints influence duplicated gene evolution. These changes are also associated with concomitant evolution of gene expression. Our findings reveal the strong conservation of genomic architecture governed by an epigenetic mark across distantly related species and the importance of gene duplication in generating novel H3K27me3 profiles.
authors.affiliation: Department of Ecology and Evolution, University of Chicago, Chicago, Illinois 60637, USA; Institute for Genomics and Systems Biology, University of Chicago and Argonne National Laboratory, Chicago, Illinois 60637, USA;
authors.forename: Robert K
authors.initials: RK
authors.lastname: Arthur
authors.affiliation: Institute for Genomics and Systems Biology, University of Chicago and Argonne National Laboratory, Chicago, Illinois 60637, USA; Department of Human Genetics, University of Chicago, Chicago, Illinois 60637, USA;
authors.forename: Lijia
authors.initials: L
authors.lastname: Ma
authors.affiliation: Institute for Genomics and Systems Biology, University of Chicago and Argonne National Laboratory, Chicago, Illinois 60637, USA; Department of Human Genetics, University of Chicago, Chicago, Illinois 60637, USA; Department of Biomedical Sciences, University of Minnesota Medical School, Duluth, Minnesota 55455, USA;
authors.forename: Matthew
authors.initials: M
authors.lastname: Slattery
authors.affiliation: Institute for Genomics and Systems Biology, University of Chicago and Argonne National Laboratory, Chicago, Illinois 60637, USA; Department of Human Genetics, University of Chicago, Chicago, Illinois 60637, USA; Department of Natural Sciences, Baruch College, City University of New York, New York 10010, USA;
authors.forename: Rebecca F
authors.initials: RF
authors.lastname: Spokony
authors.affiliation: Institute for Genomics and Systems Biology, University of Chicago and Argonne National Laboratory, Chicago, Illinois 60637, USA; Department of Human Genetics, University of Chicago, Chicago, Illinois 60637, USA;
authors.forename: Alexander
authors.initials: A
authors.lastname: Ostapenko
authors.affiliation: Institute for Genomics and Systems Biology, University of Chicago and Argonne National Laboratory, Chicago, Illinois 60637, USA; Department of Human Genetics, University of Chicago, Chicago, Illinois 60637, USA; Université de Montpellier 2 and INRA, UMR1333 DGIMI, F-34095 Montpellier, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Nègre
authors.affiliation: Department of Ecology and Evolution, University of Chicago, Chicago, Illinois 60637, USA; Institute for Genomics and Systems Biology, University of Chicago and Argonne National Laboratory, Chicago, Illinois 60637, USA; Department of Human Genetics, University of Chicago, Chicago, Illinois 60637, USA;
authors.forename: Kevin P
authors.initials: KP
authors.lastname: White
mesh_terms: D000818:Animals; D005075:Biological Evolution; D017173:Caenorhabditis elegans / Q000235:genetics / Q000378:metabolism; D002843:Chromatin / Q000235:genetics* / Q000378:metabolism*; D004330:Drosophila / Q000235:genetics / Q000378:metabolism; D019143:Evolution, Molecular; D018628:Gene Dosage; D020440:Gene Duplication; D018507:Gene Expression Regulation, Developmental; D006657:Histones / Q000378:metabolism*; D014178:Translocation, Genetic
chemical_list: D002843:Chromatin; D006657:Histones