title: Epigenetic regulation of the ELOVL6 gene is associated with a major QTL effect on fatty acid composition in pigs.
abstract: BACKGROUND
  In previous studies on an Iberian x Landrace cross, we have provided evidence that supported the porcine ELOVL6 gene as the major causative gene of the QTL on pig chromosome 8 for palmitic and palmitoleic acid contents in muscle and backfat. The single nucleotide polymorphism (SNP) ELOVL6:c.-533C > T located in the promoter region of ELOVL6 was found to be highly associated with ELOVL6 expression and, accordingly, with the percentages of palmitic and palmitoleic acids in longissimus dorsi and adipose tissue. The main goal of the current work was to further study the role of ELOVL6 on these traits by analyzing the regulation of the expression of ELOVL6 and the implication of ELOVL6 polymorphisms on meat quality traits in pigs.
  
  
  RESULTS
  High-throughput sequencing of BAC clones that contain the porcine ELOVL6 gene coupled to RNAseq data re-analysis showed that two isoforms of this gene are expressed in liver and adipose tissue and that they differ in number of exons and 3'UTR length. Although several SNPs in the 3'UTR of ELOVL6 were associated with palmitic and palmitoleic acid contents, this association was lower than that previously observed with SNP ELOVL6:c.-533C > T. This SNP is in full linkage disequilibrium with SNP ELOVL6:c.-394G > A that was identified in the binding site for estrogen receptor alpha (ERα). Interestingly, the ELOVL6:c.-394G allele is associated with an increase in methylation levels of the ELOVL6 promoter and with a decrease of ELOVL6 expression. Therefore, ERα is clearly a good candidate to explain the regulation of ELOVL6 expression through dynamic epigenetic changes in the binding site of known regulators of ELOVL6 gene, such as SREBF1 and SP1.
  
  
  CONCLUSIONS
  Our results strongly suggest the ELOVL6:c.-394G > A polymorphism as the causal mutation for the QTL on pig chromosome 8 that affects fatty acid composition in pigs.
authors.affiliation: Plant and Animal Genomics, Centre de Recerca en Agrigenòmica (Consorci CSIC-IRTA-UAB-UB), Edifici CRAG, Campus UAB, Bellaterra, Barcelona, 08193, Spain. corominas.galbany@gmail.com.|Departament de Ciència Animal i dels Aliments, Facultat de Veterinària, Campus UAB, Bellaterra, Barcelona, 08193, Spain. corominas.galbany@gmail.com.
authors.forename: Jordi
authors.initials: J
authors.lastname: Corominas
authors.affiliation: Plant and Animal Genomics, Centre de Recerca en Agrigenòmica (Consorci CSIC-IRTA-UAB-UB), Edifici CRAG, Campus UAB, Bellaterra, Barcelona, 08193, Spain. jorgea_petroli@hotmail.com.
authors.forename: Jorge A P
authors.initials: JA
authors.lastname: Marchesi
authors.affiliation: Plant and Animal Genomics, Centre de Recerca en Agrigenòmica (Consorci CSIC-IRTA-UAB-UB), Edifici CRAG, Campus UAB, Bellaterra, Barcelona, 08193, Spain. anna.puig@cragenomica.es.|Departament de Ciència Animal i dels Aliments, Facultat de Veterinària, Campus UAB, Bellaterra, Barcelona, 08193, Spain. anna.puig@cragenomica.es.
authors.forename: Anna
authors.initials: A
authors.lastname: Puig-Oliveras
authors.affiliation: Plant and Animal Genomics, Centre de Recerca en Agrigenòmica (Consorci CSIC-IRTA-UAB-UB), Edifici CRAG, Campus UAB, Bellaterra, Barcelona, 08193, Spain. manuel.revilla@cragenomica.es.|Departament de Ciència Animal i dels Aliments, Facultat de Veterinària, Campus UAB, Bellaterra, Barcelona, 08193, Spain. manuel.revilla@cragenomica.es.
authors.forename: Manuel
authors.initials: M
authors.lastname: Revilla
authors.affiliation: INRA, UMR 1313, Génétique Animale et Biologie Intégrative, Jouy-en-Josas F, 78352, France. jordi.estelle@jouy.inra.fr.|AgroParisTech, UMR 1313 Génétique Animale et Biologie Intégrative, Jouy-en-Josas F, 78352, France. jordi.estelle@jouy.inra.fr.|CEA, DSV/iRCM/SREIT/LREG, Jouy-en-Josas F, 78352, France. jordi.estelle@jouy.inra.fr.
authors.forename: Jordi
authors.initials: J
authors.lastname: Estellé
authors.affiliation: Departamento de Mejora Genética Animal, INIA, Ctra. de la Coruña km. 7, Madrid, 28040, Spain. esalves@inia.es.
authors.forename: Estefânia
authors.initials: E
authors.lastname: Alves
authors.affiliation: Plant and Animal Genomics, Centre de Recerca en Agrigenòmica (Consorci CSIC-IRTA-UAB-UB), Edifici CRAG, Campus UAB, Bellaterra, Barcelona, 08193, Spain. josepmaria.folch@uab.cat.|Departament de Ciència Animal i dels Aliments, Facultat de Veterinària, Campus UAB, Bellaterra, Barcelona, 08193, Spain. josepmaria.folch@uab.cat.
authors.forename: Josep M
authors.initials: JM
authors.lastname: Folch
authors.affiliation: Plant and Animal Genomics, Centre de Recerca en Agrigenòmica (Consorci CSIC-IRTA-UAB-UB), Edifici CRAG, Campus UAB, Bellaterra, Barcelona, 08193, Spain. mariabal77@hotmail.com.|Departament de Ciència Animal i dels Aliments, Facultat de Veterinària, Campus UAB, Bellaterra, Barcelona, 08193, Spain. mariabal77@hotmail.com.
authors.forename: Maria
authors.initials: M
authors.lastname: Ballester
mesh_terms: D000273:Adipose Tissue / Q000502:physiology; D000483:Alleles; D000818:Animals; D033481:Chromosomes, Mammalian; D003433:Crosses, Genetic; D004247:DNA / Q000032:analysis; D044127:Epigenesis, Genetic / Q000502:physiology*; D005227:Fatty Acids / Q000378:metabolism*; D015810:Linkage Disequilibrium; D009154:Mutation; D020641:Polymorphism, Single Nucleotide / Q000502:physiology*; D040641:Quantitative Trait Loci; D034421:Sus scrofa / Q000235:genetics; D013552:Swine
chemical_list: D005227:Fatty Acids; D004247:DNA