Expression of TNC Gene in Development of Bovine Skeletal Muscle and Differentiation of Preadipocytes

PurposeIn order to analyze the expression pattern of TNC gene during the development of longissimus dorsi muscle and the differentiation of preadipocyte, and the relationship between TNC gene expression level with fat deposition in beef cattle.

MethodsThe expression of TNC gene was analyzed by qRT-PCR technology in longissimus dorsi muscle tissues of 3, 6, 12, 18, 24 and 30 months old Nanyang cattle. The fat content in longissimus dorsi muscle of 24 cattle was determined by Soxhlet extraction. The preadipocyte of cattle was separated and induced differentiation with normal medium or medium with 2 μmol/L limonin, and the expression of TNC gene was analyzed by qRT-PCR technology during the differentiation of preadipocyte in control and treatment groups respectively.

ResultsThe expression of the TNC gene increased gradually in longissimus dorsi muscle after 18 month old in cattle. The muscle tissues were divided into high intramuscular fat group and low intramuscular fat group according to the fat content, and the expression levels showed no significant difference between these two groups. The expression level of TNC gene increased sharply at the 6^th hour of the differentiation, then decreased slowly, but increased again at the end of differentiation with the deposition of lipid droplet in cytoplasm. The differentiation of preadipocytes and lipid accumulation in the cytoplasm could be inhibited by limonin in medium, which also induced a significant decrease of TNC gene expression.

ConclusionTNC gene is involved in the regulation of differentiation and lipid deposition in cultivated preadipocytes and fat tissues, and the up-regulated expression of TNC gene would benefit the lipid accumulation in cytoplasm.