Data from: A functional regulatory variant of MYH3 influences muscle fiber-type composition and intramuscular fat content in pigs

Muscle development and lipid accumulation in muscle critically affect meat
quality in livestock. Yet, the underlying genetic factors for
myofiber-type specification and intramuscular fat (IMF) accumulation
remain to be elucidated. Using two independent intercrosses between
Western breeds and Korean native pigs (KNPs) and a joint linkage-linkage
disequilibrium analysis, we here identified a 488.1-kb region on porcine
chromosome 12 that affects both reddish meat color (a*) and IMF. In this
critical region, only the MYH3 gene, encoding myosin heavy chain 3, was
found to be preferentially overexpressed in the skeletal muscle in KNPs.
Subsequently, MYH3-transgenic mice demonstrated that this gene controls
both myofiber-type specification and adipogenesis in skeletal muscle. We
discovered a structural variant in the promotor/regulatory region of MYH3
for which Q allele carriers exhibited significantly higher values of a*
and IMF than q allele carriers. Furthermore, chromatin immunoprecipitation
and co-transfection assays showed the structural variant in the
5'-UTR of MYH3 abrogated binding of the myogenic regulatory factors
(MYF5, MYOD, MYOG, and MRF4). The allele distribution of the MYH3 among
worldwide pig populations indicated that the MYH3 Q allele is of Asian
origin and likely predates domestication. In conclusion, we identified a
functional regulatory sequence variant in the porcine MYH3 that provides
novel insights into the genetic basis of the regulation of myofiber type
ratios and associated changes in IMF in pigs. The MYH3 variant can play an
important role to improve pork quality in current breeding programs.