The RN− (rendement Napole, French for Napole yield) phenotype is common in Hampshire pigs and is characterized by a 70% increase in glycogen content in skeletal muscle and large effects on meat characteristics (pH, water content, technological yield and lean meat content). The phenotype is controlled by an autosomal dominant allele designated RN−. The protein kinase AMP-activated γ3 subunit gene, PRKAG3, which encodes the γ3 isoform of AMP-activated protein kinase (AMPK), was identified as the causative gene for this phenotype by a pure positional cloning approach. There are now several lines of evidence supporting our interpretation that the RN− phenotype is caused by a missense mutation (Arg200→Gln) in PRKAG3. Recent data from another group have revealed the presence of a third functional allele at the PRKAG3 locus, probably caused by a Val199→Ile missense mutation. This allele has opposite effects compared with RN, as it is associated with a low glycogen content. We have confirmed the phenotypic effect of this third allele in a meat-quality study of a Hampshire/Landrace intercross. A physiological characterization of RN− carriers and normal pigs showed that the RN− pigs utilized glycogen during exercise to the same extent as normal pigs and they showed a significantly faster resynthesis of glycogen after exercise. The results strongly suggest that the Arg200→Gln substitution is not associated with a defect in glycogen degradation, but rather with an increased glucose uptake in skeletal muscle.
Skip Nav Destination
Article navigation
February 2003
- PDF Icon PDF LinkFront Matter
Conference Article|
February 01 2003
Identification and characterization of AMPK γ3 mutations in the pig
L. Andersson
L. Andersson
1
Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Box 597, S-751 24 Uppsala, Sweden
1To whom correspondence should be addressed (e-mail Leif.Andersson@bmc.uu.se).
Search for other works by this author on:
Publisher: Portland Press Ltd
Online ISSN: 1470-8752
Print ISSN: 0300-5127
Copyright 2003 Biochemical Society
2003
Biochem Soc Trans (2003) 31 (1): 232–235.
Citation
L. Andersson; Identification and characterization of AMPK γ3 mutations in the pig. Biochem Soc Trans 1 February 2003; 31 (1): 232–235. doi: https://doi.org/10.1042/bst0310232
Download citation file:
Sign in
Don't already have an account? Register
Sign in to your personal account
You could not be signed in. Please check your email address / username and password and try again.
Captcha Validation Error. Please try again.