Heat-Shock Protein Beta 1 Is Related to Muscle Growth and Development in Beef Cattle

Muscle growth and development is critical for the meat production of beef cattle. Previous studies have suggested that heat-shock protein beta 1 (HSPB1) is a candidate protein related to muscle development in cattle. In this study, we aimed to examine the association between HSPB1 and muscle development in Korean native cattle. In addition, we also sought to identify novel single nucleotide polymorphisms (SNPs) of HSPB1 gene which may be related to muscle growth in Korean native cattle. In this research, we conducted both in vitro cell culture and HSPB1 SNP genotyping experiment. In in vitro cell culture experiments, we used MyoD (myogenic lineage determinant) over-expressed immortalized bovine embryonic fibroblast cell line (BEFS-MyoD cell) to find out the role of HSPB1 in bovine myogenesis. First, siRNA assay of HSPB1 expression was conducted in BEFS-MyoD cell to evaluate the effect of reduced HSPB1 expression on myogenic differentiation stages. Second, to elucidate the role of higher HSPB1 expression in myogenesis, we also carried out glutamine (HSPB1 inducer)-mediated bovine myogenesis in BEFS-MyoD cell. For genotyping experiments, direct DNA sequencing of HSPB1 gene was performed to find out novel SNPs associated with muscle development in 20 unrelated Korean native cattle. The inhibition of HSPB1 expression has shown to repress the expression of myogenic marker genes (MyoD, Myogenin, Desmin) (p<0.01), and formation of myotubes. In contrast, higher expression of HSPB1 enhanced the expression myogenic marker genes (p<0.01), myotubes formation, and protein synthesis (p<0.01). Direct DNA sequencing of HSPB1 revealed three 3 sequence variants located in the coding region, 5´UTR, and intron region in 20 unrelated Korean native cattle. Among these SNPs, g.2352 T>C and g.111 T>C SNPs are located nearby a splicing site and a cis-regulatory site. According to the results, it is concluded that HSPB1 enhances muscle growth and development, and novel variants found in three distinct genomic regions might be used as candidate markers for muscle development in Korean native cattle.