Preliminary report of arginine on synthesis and gene expression of casein in bovine mammary epithelial cell

Abstract

Chen LM, Li ZT, Wang MZ and Wang HR

In this experiment, the effects of arginine levels on the synthesis and gene expressions of αs-casein and β-casein were assayed by bovine mammary epithelial cell. The treatments were designed as follows, Arg 0.25× group (69.50 mg/L), 0.5× group (139.00 mg/L), 1× group (278.00 mg/L), 2× group (556.00 mg/L), 4× group (1, 112 mg/L), 8× group (2, 224 mg/L) as experimental group respectively, and Arg 0× group (0.00 mg/L) was set as the control group. αs-casein and β-casein synthesis were tested using the ELISA kit, and the CSN1S1 and CSN2 gene expression was examined by RT-PCR method. The results showed that, compared to the control group, αs-casein synthesis in the Arg 0.5×, Arg 1× and Arg 2× group was significantly higher (P < 0.05), and highest in the Arg 2× group (P < 0.05). As for β-casein, the experimental groups were higher than control group (P < 0.05) except for the Arg 0.25× group; was also highest in the Arg 2× group (P < 0.05). It was also observed that, all experimental groups were higher than the control group in the relative expression quantities of CSN1S1 gene significantly (P < 0.05); and also higher than the control group in CSN2 gene (P < 0.05), except for the Arg 8× group. And similarly, CSN1S1 and CSN2 were all highest in the Arg 2× group (P < 0.05). In conclusion, the synthesis of αs-casein and β-casein and the expressions of CSN1S1 and CSN2 gene were all manipulated by arginine levels; and the Arg 2× group containing 556.00 mg/L arginine in medium demonstrated the highest impact.