Expression of OPN gene during different lactation stages in mammary gland of dairy goat and its effect on growth of MCF-7 cell line
不同泌乳期奶山羊乳腺OPN基因表达及其对MCF-7细胞生长的影响

To investigate the expression pattern and preliminary function of OPN gene in mammary gland of dairy goat dur-ing different lactation stages, using b-actin gene as the internal control, the SYBR Green quantitative real-time PCR (QPCR) analysis was conducted to determine the mRNA expression of OPN gene in mammary gland at the 28th, 60th, 100th, 190th, 270th and 330th day after kidding. Recombinant plasmid of pcDNA3.1-OPN was constructed by inserting the fragment of OPN gene into eukaryotic expression vector pcDNA3.1 and used to transfect the MCF-7 cell line following the restrictive en-donuclease cleavage and sequence identification of the target gene segment, the effect of OPN gene on MCF-7 cell prolifera-tion was assessed by MTT analysis. The results indicated that OPN gene exhibited the higher expression level in early (28 d) and late (190 d) lactation stages and the lowest level at dry stage (330 d), which demonstrated a high-low-high-low pattern. There was a significant difference (P < 0. 05) in the proliferation between OPN gene transfected and non-transfected MCF-7 cells, which suggested that the expression of OPN gene could stimulate the proliferation of MCF-7 cells.