Genetic variation at the porcine MYF-5 gene locus. Lack of association with meat production traits

The number of muscle fibers at birth appears to determine the maximal lean meat growth capacity in pigs and in cattle. Development of muscle fibers is regulated by the MyoD gene family consisting of MyoD1, myf-5, myf-6, and m yogenin. Myf-5 is expressed in proliferating myoblasts. Here we report the genomic sequence of the porcine myf-5 gene with three microsatellites and t wo RFLPs located close to the coding sequences. Two of the microsatellites are located in the promoter region. The allelic distribution differs betwee n breeds and selection lines. In two GY selection lines, 1216 pigs of two-g eneration families were genotyped for the HinfI RFLP, which was segregating in the GY breed. The other polymorphic loci are physically linked to this RFLP locus, and therefore the results can be extrapolated to these loci. St atistical analysis revealed no association with birth weight, growth rate, weight at slaughter age, carcass meat weight, and backfat thickness. Thus, in this study myf-5 did not explain genetic variation in meal (muscle) deve lopment in pigs.