title: Identification of KCNJ11 as a functional candidate gene for bovine meat tenderness.
abstract: The potassium inwardly rectifying channel, subfamily J, member 11 (KCNJ11) gene was investigated as a candidate for meat tenderness based on the effects reported on muscle for KCNJ11 gene knockout in rat models and its position in a quantitative trait locus (QTL) for meat tenderness in the bovine genome. Sequence variations in the KCNJ11 gene were described by sequencing six amplified fragments, covering almost the entire gene. We identified single nucleotide polymorphisms (SNP) and validated them by different approaches, taking advantage of simultaneous projects that are being developed with the same Nelore population. By sequencing the KCNJ11 in Nelore steers representing extreme phenotypes for Warner-Bratzler shear force (WBSF), it was possible to identify 22 SNPs. We validated two of the identified markers by genotyping the whole population (n = 460). Analysis of association between genotypes and WBSF values revealed a significant additive effect of a SNP at different meat aging times (P ≤ 0.05). In addition, an association between the expression levels of KCNJ11 and WBSF was found, with lower expression levels of KCNJ11 associated with more tender meat (P ≤ 0.05). The results showed that the KCNJ11 gene is a candidate mapped to a QTL for meat tenderness previously identified on BTA15 and may be useful to identify animals with genetic potential to produce tender meat. The effect of KCNJ11 observed on muscle is potentially due to changes in activity of KATP channels, which in turn influence the flow of potassium in the intracellular space, allowing establishment of the membrane potential necessary for muscle contraction.
authors.affiliation: Departamento de Genética e Evolução, Universidade Federal de São Carlos, São Carlos, São Paulo, Brazil;
authors.forename: Polyana C
authors.initials: PC
authors.lastname: Tizioto
authors.forename: Gustavo
authors.initials: G
authors.lastname: Gasparin
authors.forename: Marcela M
authors.initials: MM
authors.lastname: Souza
authors.forename: Mauricio A
authors.initials: MA
authors.lastname: Mudadu
authors.forename: Luiz L
authors.initials: LL
authors.lastname: Coutinho
authors.forename: Gerson B
authors.initials: GB
authors.lastname: Mourão
authors.forename: Patricia
authors.initials: P
authors.lastname: Tholon
authors.forename: Sarah L C
authors.initials: SL
authors.lastname: Meirelles
authors.forename: Rymer R
authors.initials: RR
authors.lastname: Tullio
authors.forename: Antônio N
authors.initials: AN
authors.lastname: Rosa
authors.forename: Maurício M
authors.initials: MM
authors.lastname: Alencar
authors.forename: Sérgio R
authors.initials: SR
authors.lastname: Medeiros
authors.forename: Fabiane
authors.initials: F
authors.lastname: Siqueira
authors.forename: Gelson L D
authors.initials: GL
authors.lastname: Feijó
authors.forename: Renata T
authors.initials: RT
authors.lastname: Nassu
authors.forename: Luciana C A
authors.initials: LC
authors.lastname: Regitano
mesh_terms: D000818:Animals; D001483:Base Sequence; D002417:Cattle; D017931:DNA Primers; D008461:Meat Products; D018482:Muscle, Skeletal; D020641:Polymorphism, Single Nucleotide; D024661:Potassium Channels, Inwardly Rectifying / Q000235:genetics*; D040641:Quantitative Trait Loci; D000099161:Kcnj11 Channel
chemical_list: D017931:DNA Primers; D024661:Potassium Channels, Inwardly Rectifying; D000099161:Kcnj11 Channel
keywords: Warner-Bratzler shear force; beef; differential expression; molecular markers