Expression of ADAMTS4 and ADAMTS5 in longissimus dorsi muscle related to meat tenderness in Nanyang cattle

The ADAMTS4 and ADAMTS5 are secreted proteases, which can cleave aggrecan, brevican and versican to regulate rebuilding of the extracellular matrix. We analyzed the ADAMTS4 and ADAMTS5 gene expression patterns in longissimus dorsi muscle at intervals from 135 days fetal age to 30 months old by qRT-PCR in Nanyang cattle. Expression of ADAMTS4 was significantly higher in 135 and 185-day-old fetuses than at other stages, while expression of ADAMTS5 decreased during development. The promoter regions of ADAMTS4 and ADAMTS5 were cloned and the transcription factor binding sites were analyzed with bioinformatic methods. Twelve and six potential transcription factor binding sites were found in the promoter regions of ADAMTS4 and ADAMTS5 genes, respectively. Three transcription factors (MZF1, C/EBPb, and NF-kap) were selected to analyze the expression pattern during the development of the longissimus dorsi muscle. MZF1 was significantly co-expressed with ADAMTS4, while C/EBPb expression was significantly negatively associated with that of ADAMTS4. We concluded that the expression of ADAMTS4 is positively regulated by MZF1 and negatively regulated by C/EBPb. We examined the relationships of ADAMTS4 and ADAMTS5 expression with tenderness of longissimus