title: Meiotic behaviour of evolutionary sex-autosome translocations in Bovidae.
abstract: The recurrent occurrence of sex-autosome translocations during mammalian evolution suggests common mechanisms enabling a precise control of meiotic synapsis, recombination and inactivation of sex chromosomes. We used immunofluorescence and FISH to study the meiotic behaviour of sex chromosomes in six species of Bovidae with evolutionary sex-autosome translocations (Tragelaphus strepsiceros, Taurotragus oryx, Tragelaphus imberbis, Tragelaphus spekii, Gazella leptoceros and Nanger dama ruficollis). The autosomal regions of fused sex chromosomes showed normal synapsis with their homologous counterparts. Synapsis in the pseudoautosomal region (PAR) leads to the formation of characteristic bivalent (in T. imberbis and T. spekii with X;BTA13/Y;BTA13), trivalent (in T. strepsiceros and T. oryx with X/Y;BTA13 and G. leptoceros with X;BTA5/Y) and quadrivalent (in N. dama ruficollis with X;BTA5/Y;BTA16) structures at pachynema. However, when compared with other mammals, the number of pachynema lacking MLH1 foci in the PAR was relatively high, especially in T. imberbis and T. spekii, species with both sex chromosomes involved in sex autosome translocations. Meiotic transcriptional inactivation of the sex-autosome translocations assessed by γH2AX staining was restricted to their gonosomal regions. Despite intraspecies differences, the evolutionary fixation of sex-autosome translocations among bovids appears to involve general mechanisms ensuring sex chromosome pairing, synapsis, recombination and inactivation.
authors.affiliation: Department of Genetics and Reproduction, Central European Institute of Technology-Veterinary Research Institute, Hudcova 70, 621 00, Brno, Czech Republic. vozdova@vri.cz.
authors.forename: Miluse
authors.initials: M
authors.lastname: Vozdova
authors.affiliation: Genome Integrity and Instability Group, Institut de Biotecnologia i Biomedicina (IBB), Universitat Autònoma de Barcelona, Campus UAB, 08193, Bellaterra, Barcelona, Spain.|Departament de Biologia Cel.lular, Fisiologia i Immunologia, Universitat Autònoma de Barcelona, Campus UAB, 08193, Bellaterra, Barcelona, Spain.
authors.forename: Aurora
authors.initials: A
authors.lastname: Ruiz-Herrera
authors.affiliation: Genome Integrity and Instability Group, Institut de Biotecnologia i Biomedicina (IBB), Universitat Autònoma de Barcelona, Campus UAB, 08193, Bellaterra, Barcelona, Spain.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Fernandez
authors.affiliation: Department of Genetics and Reproduction, Central European Institute of Technology-Veterinary Research Institute, Hudcova 70, 621 00, Brno, Czech Republic.
authors.forename: Halina
authors.initials: H
authors.lastname: Cernohorska
authors.affiliation: Department of Genetics and Reproduction, Central European Institute of Technology-Veterinary Research Institute, Hudcova 70, 621 00, Brno, Czech Republic.
authors.forename: Jan
authors.initials: J
authors.lastname: Frohlich
authors.affiliation: Department of Genetics and Reproduction, Central European Institute of Technology-Veterinary Research Institute, Hudcova 70, 621 00, Brno, Czech Republic.
authors.forename: Hana
authors.initials: H
authors.lastname: Sebestova
authors.affiliation: Department of Genetics and Reproduction, Central European Institute of Technology-Veterinary Research Institute, Hudcova 70, 621 00, Brno, Czech Republic.
authors.forename: Svatava
authors.initials: S
authors.lastname: Kubickova
authors.affiliation: Department of Genetics and Reproduction, Central European Institute of Technology-Veterinary Research Institute, Hudcova 70, 621 00, Brno, Czech Republic.
authors.forename: Jiri
authors.initials: J
authors.lastname: Rubes
mesh_terms: D000818:Animals; D020223:Chromosome Painting; D023902:Chromosome Pairing / Q000235:genetics*; D020090:Chromosome Segregation / Q000235:genetics*; D005455:Fluorescent Antibody Technique; D017404:In Situ Hybridization, Fluorescence; D008540:Meiosis / Q000235:genetics*; D012418:Ruminants / Q000235:genetics*; D012730:Sex Chromosomes / Q000235:genetics*; D014178:Translocation, Genetic
keywords: Bovidae; Histone modification; Meiosis; Recombination; Sex-autosome translocation; Sex-chromosome inactivation; Synapsis; X chromosome; Y chromosome