Abstract: 【Objective】The objectives of this study were to investigate the developmental changes of the PPARγ and C/EBPα mRNA expression level in different tissues，months and breeds, and its effect on intramuscular fat accumulation in pig. 【Method】Jiangkou Luobo Pig, Congjiang Xiang Pig and Large White Pig were slaughtered at 3, 4, 5, 6, and 7 months to collect samples from heart, liver, spleen, lung, kidney, small intestine, longissimus dorsi, and subcutaneous adipose for the purpose of determing the IMF content in Longissimus dorsi and extracting total RNA in order to investigate the developmental changes of the PPARγ and C/EBPα expression by real - time PCR.【Result】By real-time PCR, PPARγ and C/EBPα had the mRNA expression in all tissues of Large White Pig at 3, 4, 5, 6, and 7 months, but highly in liver, small intestine, longissimus dorsi, subcutaneous adipose, lowly in heart, spleen, lung, and kidney. The expression levels of PPARγ in the small intestine, longissimus dorsi, and subcutaneous adipose at 3, 4 months were extremely different with that at 6, and 7 months (P＜0.01). The expression levels of C/EBPα in the liver, lung, small intestine, and subcutaneous adipose at 3 month was extremly different with that at 6, and 7 months (P＜0.01); The mRNA expression of PPARγ and C/EBPα were lower in heart, spleen, lung, kidney, and longissimus dorsi of Jiangkou Luobo Pig, higher in subcutaneous adipose with issue-specificity. The expression amount increased with the age, and the increase of subcutaneous fat was the most. The expression levels of PPARγ in the small intestine, longissimus dorsi, and subcutaneous adipose at 3, and 4 months also were extremely different with that at 6, and 7 months (P＜0.01). The expression levels of C/EBPα in the small intestine, subcutaneous adipose at 3 month were extremely different with that at 5, 6, and 7 months (P＜0.01). The mRNA expression of PPARγ and C/EBPα in the Subcutaneous adipose of Congjiang Xiang Pig was the highest. The expression of PPAR was not significantly increased with the age. The expression of C/EBPα was significantly increased with the age. The expression levels of PPARγ and C/EBPα in the small intestine, longissimus dorsi, and subcutaneous adipose at 3, 4 months were different with that at 6, and7 months (P＜0.05). With growing, the mRNA expression levels of PPARγ and C/EBPα were basically the same in the model, and showed an increasing trend, then maintained the higher expression levels in 6, and 7 months. The mRNA expression levels of PPARγ and C/EBPα were gradually increased with the increase of the age and maintained a relatively stable level at the late growth stage. The expression of PPARγ and C/EBPα was the highest in Subcutaneous adipose, the higher in Liver, Lung, Small intestine, and the lowest in heart, spleen, and kidney. The PPARγ and C/EBPα mRNA expression in different tissues of Jiangkou Luobo Pig, Congjiang Xiang Pig were higher than that of Large White Pig. The correlation of gene expression and IMF content showed that the PPARγ and C/EBPα expression level were positively related to IMF content. 【Conclusion】It was inferred that PPARγ and C/EBPα gene may be related to regulatory mechanism of lipid metabolism and fat deposition.

Key words: pig, PPARγ, C/EBPα, gene expression, intramuscular fat