title: Strong artificial selection in domestic mammals did not result in an increased recombination rate.
abstract: Recombination rates vary in intensity and location at the species, individual, sex and chromosome levels. Despite the fundamental biological importance of this process, the selective forces that operate to shape recombination rate and patterns are unclear. Domestication offers a unique opportunity to study the interplay between recombination and selection. In domesticates, intense selection for particular traits is imposed on small populations over many generations, resulting in organisms that differ, sometimes dramatically, in morphology and physiology from their wild ancestor. Although earlier studies suggested increased recombination rate in domesticates, a formal comparison of recombination rates between domestic mammals and their wild congeners was missing. In order to determine broad-scale recombination rate, we used immunolabeling detection of MLH1 foci as crossover markers in spermatocytes in three pairs of closely related wild and domestic species (dog and wolf, goat and ibex, and sheep and mouflon). In the three pairs, and contrary to previous suggestions, our data show that contemporary recombination rate is higher in the wild species. Subsequently, we inferred recombination breakpoints in sequence data for 16 genomic regions in dogs and wolves, each containing a locus associated with a dog phenotype potentially under selection during domestication. No difference in the number and distribution of recombination breakpoints was found between dogs and wolves. We conclude that our data indicate that strong directional selection did not result in changes in recombination in domestic mammals, and that both upper and lower bounds for crossover rates may be tightly regulated.
authors.affiliation: Conservation and Evolutionary Genetics Group, Estación Biológica de Doñana EBD-CSIC, Sevilla, Spain Department of Population and Conservation Biology, Uppsala University, Uppsala, Sweden vmfuentes@senckenberg.de vmfuentes@senckenberg.de.
authors.forename: Violeta
authors.initials: V
authors.lastname: Muñoz-Fuentes
authors.affiliation: Genome Integrity and Instability Group, Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain Cytology and Histology Unit, Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain.
authors.forename: Marina
authors.initials: M
authors.lastname: Marcet-Ortega
authors.affiliation: Department of Human Genetics, Cummings Life Science Center, University of Chicago.
authors.forename: Gorka
authors.initials: G
authors.lastname: Alkorta-Aranburu
authors.affiliation: Division of Reproduction, Swedish University of Agricultural Sciences, Uppsala, Sweden.
authors.forename: Catharina
authors.initials: C
authors.lastname: Linde Forsberg
authors.affiliation: Division of Reproduction, Swedish University of Agricultural Sciences, Uppsala, Sweden.
authors.forename: Jane M
authors.initials: JM
authors.lastname: Morrell
authors.affiliation: Conservation and Evolutionary Genetics Group, Estación Biológica de Doñana EBD-CSIC, Sevilla, Spain.
authors.forename: Esperanza
authors.initials: E
authors.lastname: Manzano-Piedras
authors.affiliation: Department of Pathology and Wildlife Diseases, National Veterinary Institute (SVA), Uppsala, Sweden.
authors.forename: Arne
authors.initials: A
authors.lastname: Söderberg
authors.affiliation: Institute of Physiological Chemistry, Technische Universität Dresden, Dresden, Germany.
authors.forename: Katrin
authors.initials: K
authors.lastname: Daniel
authors.affiliation: Genome Integrity and Instability Group, Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain Cytology and Histology Unit, Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain.
authors.forename: Adrian
authors.initials: A
authors.lastname: Villalba
authors.affiliation: Institute of Physiological Chemistry, Technische Universität Dresden, Dresden, Germany.
authors.forename: Attila
authors.initials: A
authors.lastname: Toth
authors.affiliation: Department of Human Genetics, Cummings Life Science Center, University of Chicago.
authors.forename: Anna
authors.initials: A
authors.lastname: Di Rienzo
authors.affiliation: Genome Integrity and Instability Group, Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain Cytology and Histology Unit, Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain.
authors.forename: Ignasi
authors.initials: I
authors.lastname: Roig
authors.affiliation: Conservation and Evolutionary Genetics Group, Estación Biológica de Doñana EBD-CSIC, Sevilla, Spain.
authors.forename: Carles
authors.initials: C
authors.lastname: Vilà
mesh_terms: D000818:Animals; D046028:Canidae / Q000235:genetics; D004285:Dogs; D005260:Female; D014644:Genetic Variation / Q000235:genetics*; D023281:Genomics; D006041:Goats / Q000235:genetics; D008297:Male; D008322:Mammals; D011995:Recombination, Genetic / Q000235:genetics*; D012756:Sheep / Q000235:genetics; D013090:Spermatocytes / Q000378:metabolism
keywords: Canis; Capra; MLH1; Ovis; genomics; immunolocalization; spermatocytes