[CDS cloning and relationship between intramuscular fat content and mRNA expression of PID1 gene in pig]

To explore the relationship between the expression of PID1 gene and fat deposition, we cloned CDS of PID1 from porcine fat and muscle tissues by RT-PCR using degenerate primers, and investigated expression of this gene in various tissues (i.e., liver, backfat, and muscle tissues) of different breeds (i.e., Yorkshire, Laiwu, and Lulai Black) by real-time fluorescence quantitative PCR. The results showed that 654 bp CDS of porcine PID1 was obtained by sequencing and was 93.88%, 66.94% and 88.07% identical to those of the human, rat, and Bos taurus, respectively. The expression of PID1 mRNA in various tissues and breeds, on the whole, tended to be liver > fat > muscle and Laiwu > Lulai Black > Yorkshire, respectively. For different breeds, PID1 mRNA abundance in liver had significant difference (P < 0.05), but had no significant differences in fat and muscle tissues between Laiwu and Lulai Black (P > 0.05). For the three groups of Laiwu pigs with high (LWH), intermediate (LWI), and low IMF content (LWL), PID1 mRNA level was higher in liver tissue of LWH than that of LWL significantly (P < 0.05), and was higher in muscle tissue of LWH than that of LWI and LWL significantly (P < 0.05). PID1 mRNA abundance was not correlated with IMF in these three tissues of Laiwu breed, but it was positively correlated with IMF in the tissues of these three breeds (P < 0.05). These results implied that the expression of PID1 may be related to fat deposition.