title: Sperm DNA methylation analysis in swine reveals conserved and species-specific methylation patterns and highlights an altered methylation at the GNAS locus in infertile boars.
abstract: Male infertility is an increasing health issue in today's society for both human and livestock populations. In livestock, male infertility slows the improvement of animal selection programs and agricultural productivity. There is increasing evidence that epigenetic marks play an important role in the production of good-quality sperm. We therefore screened for specific or common epigenetic signatures of livestock infertility. To do so, we compared DNA methylation level in sperm DNA from fertile and infertile boars. We evaluated first the global level of sperm DNA methylation and found no difference between the two groups of boars. We then selected 42 loci of interest, most of them known to be imprinted in human or mice, and assessed the imprinting status of five of them not previously described in swine tissues: WT1, CNTN3, IMPACT, QPCT, and GRB10. DNA methylation level was then quantified in fertile and infertile boars at these 42 loci. Results from fertile boars indicated that the methylation level of the selected loci is highly conserved between pig, human, and mice, with a few exceptions, including the POU5F1 (OCT4) promoter and RTL1. Comparison between fertile and infertile boars revealed that one imprinted region, the GNAS locus, shows an increase in sperm DNA methylation in three out of eight infertile boars with low semen quality. This increase in DNA methylation is associated with an altered expression of the genes belonging to the GNAS locus, suggesting a new role for GNAS in the proper formation of functional gametes.
authors.affiliation: INRA, UMR1388 Génétique, Physiologie et Systèmes d'Elevage, GenPhySE, Castanet-Tolosan, France.
authors.forename: Annabelle
authors.initials: A
authors.lastname: Congras
authors.affiliation: INRA, UMR1388 Génétique, Physiologie et Systèmes d'Elevage, GenPhySE, Castanet-Tolosan, France.
authors.forename: Martine
authors.initials: M
authors.lastname: Yerle-Bouissou
authors.affiliation: Université de Toulouse INPT ENVT, UMR1388 Génétique Physiologie et Systèmes d'Elevage GenPhySE, Toulouse, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Pinton
authors.affiliation: INRA, UMR1388 Génétique, Physiologie et Systèmes d'Elevage, GenPhySE, Castanet-Tolosan, France.
authors.forename: Florence
authors.initials: F
authors.lastname: Vignoles
authors.affiliation: INRA, UMR1388 Génétique, Physiologie et Systèmes d'Elevage, GenPhySE, Castanet-Tolosan, France.
authors.forename: Laurence
authors.initials: L
authors.lastname: Liaubet
authors.affiliation: UE1372 GenESI Génétique, Expérimentation et Système Innovants, Surgères, France.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Ferchaud
authors.affiliation: INRA, UMR1388 Génétique, Physiologie et Systèmes d'Elevage, GenPhySE, Castanet-Tolosan, France herve.acloque@toulouse.inra.fr.
authors.forename: Hervé
authors.initials: H
authors.lastname: Acloque
mesh_terms: D000818:Animals; D017124:Conserved Sequence; D019175:DNA Methylation; D044127:Epigenesis, Genetic; D005260:Female; D019205:GTP-Binding Protein alpha Subunits, Gs / Q000235:genetics*; D020869:Gene Expression Profiling; D056426:Genetic Loci; D018392:Genomic Imprinting; D007248:Infertility, Male / Q000235:genetics* / Q000378:metabolism; D008297:Male; D011247:Pregnancy; D055101:Semen Analysis; D013045:Species Specificity; D013094:Spermatozoa / Q000378:metabolism*; D013552:Swine / Q000235:genetics*
chemical_list: D019205:GTP-Binding Protein alpha Subunits, Gs
keywords: DNA methylation; GNAS; imprinted gene; infertility; pig; sperm; swine