Abstract: In order to find the genetic mechanism which impact on the meat quanlity in different development stages of bovine at the molecular levels, we used mRNA differential display reverse-transcription PCR (DDRT-PCR) to identify differentially expressed genes in different development stages of bovine skeletal muscles. A total of 6 ESTs were found and subsequently compared with the nucleotide sequences in GenBank database using BLAST. S1 was highly similar to the bovine coffilin 2(CFL2) gene, the others(S2 to S6) were no significant similarity with existing genes or ESTs and were reguarded as the new EST. The mRNA expression of CFL2 gene was examined by relative quantitative PCR. The results indicated that the expression of CFL2 of 5 years old Mongolia bovine’s muscle tissue was 3.8 times more than 16 months old one’s. It was well known that the excessive expression of CFL2 could inhibit G-actin polymerization and accumulation of high quality type 1 muscle fiber, therefore, it demonstrated that the high expression of CFL2 gene might cause decline of the meat traits of Mongolia bovine.

Key words: Mengolia bovine; mRNA differential display; skeletal muscle