Premium
DNA polymorphisms and transcript abundance of PRKAG 2 and phosphorylated AMP ‐activated protein kinase in the rumen are associated with gain and feed intake in beef steers
Author(s) -
LindholmPerry A. K.,
Kuehn L. A.,
Oliver W. T.,
Kern R. J.,
Cushman R. A.,
Miles J. R.,
McNeel A. K.,
Freetly H. C.
Publication year - 2014
Publication title -
animal genetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.756
H-Index - 81
eISSN - 1365-2052
pISSN - 0268-9146
DOI - 10.1111/age.12151
Subject(s) - biology , rumen , ampk , feed conversion ratio , protein kinase a , beef cattle , zoology , genetics , endocrinology , kinase , biochemistry , body weight , fermentation
Summary Beef steers with variation in feed efficiency phenotypes were evaluated previously on a high‐density SNP panel. Ten markers from rs110125325–rs41652818 on bovine chromosome 4 were associated with average daily gain ( ADG ). To identify the gene(s) in this 1.2‐Mb region responsible for variation in ADG , genotyping with 157 additional markers was performed. Several markers ( n = 41) were nominally associated with ADG , and three of these, including the only marker to withstand B onferroni correction, were located within the protein kinase, AMP ‐activated, gamma 2 non‐catalytic subunit ( PRKAG 2 ) gene. An additional population of cross‐bred steers ( n = 406) was genotyped for validation. One marker located within the PRKAG 2 loci approached a significant association with gain. To evaluate PRKAG 2 for differences in transcript abundance, we measured expression in the liver, muscle, rumen and intestine from steers ( n = 32) with extreme feed efficiency phenotypes collected over two seasons. No differences in PRKAG 2 transcript abundance were detected in small intestine, liver or muscle. Correlation between gene expression level of PRKAG 2 in rumen and average daily feed intake ( ADFI ) was detected in both seasons ( P < 0.05); however, the direction differed by season. Lastly, we evaluated AMP ‐activated protein kinase ( AMPK ), of which PRKAG 2 is a subunit, for differences among ADG and ADFI and found that the phosphorylated form of AMPK was associated with ADFI in the rumen. These data suggest that PRKAG 2 and its mature protein, AMPK , are involved in feed efficiency traits in beef steers. This is the first evidence to suggest that rumen AMPK may be contributing to ADFI in cattle.