Expression patterns and promoter activity analysis of UGP2 in pigs.

The function of the UDP-glucose pyrophosphorylase 2 gene (UGP2) in pig is not clear. In the present study, we used RNA isolated from Large White pigs and Chinese indigenous MeiShan pigs to examine the temporal coordination of changes in gene expression within muscle tissues. We cloned both the complete genomic DNA sequence and 2077-bp 5ꞌ-flanking sequence of porcine UGP2, to determine the genomic sequence. Real-time RT-PCR revealed that UGP2 was highly expressed in liver and skeletal muscle of MeiShan pigs. Among different types of muscle fibers, the UGP2 had the highest expression in both soleus muscle and longissimus dorsi in Large White pigs. In the progression of muscle fibers at different growth stages, UGP2 plays a role in the early days after birth in Large White pigs, while in MeiShan pigs it is important later. Furthermore, the 5ꞌ-flanking sequence we cloned exhibited the promoter activity of UGP2, and the sequence 588 bp upstream from the transcriptional site had the greatest activity.