This study used qRT-PCR to examine variation in the expression of 13 myogenes during
muscle development in four prenatal periods (21, 40, 70 and 90 days
post-insemination) in commercial (the three-way Duroc, Landrace and Large-White
cross) and local Piau pig breeds that differ in muscle mass. There was no variation
in the expression of the CHD8, EID2B, HIF1AN, IKBKB, RSPO3, SOX7 and
SUFU genes at the various prenatal ages or between breeds. The
MAP2K1 and RBM24 genes showed similar expression
between commercial and Piau pigs but greater expression (p < 0.05) in at least one
prenatal period. Pair-wise comparisons of prenatal periods in each breed showed that
only the CSRP3, LEF1, MRAS and MYOG genes had
higher expression (p < 0.05) in at least one prenatal period in commercial and
Piau pigs. Overall, these results identified the LEF1 gene as a
primary candidate to account for differences in muscle mass between the pig breeds
since activation of this gene may lead to greater myoblast fusion in the commercial
breed compared to Piau pigs. Such fusion could explain the different muscularity
between breeds in the postnatal periods.