The Differences Of PPARGC1A Gene Expression Of Different Tissues And Developmental Stages In Pigs

Peroxisome proliferative activated receptorγcoactivator 1A(PPARGC1A) is a transcription factor of PPARγ,there are a variety of nuclear hormone receptor binding site. PPARGC1A plays an important role in adipogenesis and adipocyte differentiation, mitochondrial biogenesis and respiration,and hepatic gluconeogenesis.At the same time it can also induce glycolytic fibers conversion to oxidative fibers,thereby improving meat quality.Besides,PPARGC1A can bind to myocyte-specific enhancer 2C(MEF2C) to regulate the expression of another candidate gene for meat quality like glucose transporter 4(GLUT4).PPARGC1A has become a new hotspot of candidate gene with regard to meat quality in pork.Usingβ-actin as internal standard control,the regular of PPARGC1A gene mRNA expression levels which was in different breeds,different tissues and different physiological phases was investigated by TaqMan probe real-time PCR assay for quantitative analysis,and to investigate the relationships between PPARGC1A gene expression and carcass traits from two genotypes of pigs.The results are as follows:1.Development patterns of PPARGC1A mRNA expression in longissmus muscle were similar in longissmus muscle.They were increased first and decreased afterwards.For Taihu pigs,PPARGC1A gene expression was higher at 1 month than other months(P＜0.05),then declined sharply at 3 months,continuously increased by 5 months.For Landrace,PPARGC1A gene expression was significantly higher at 2 months than other months(P＜0.05),then continuously declined at 5 months.The expression level of PPARGC1A mRNA in Landrace was higher than that of Taihu pigs at the age of 0 and 2 months(P＜0.05),The expression level of PPARGC1A mRNA in Landrace was higher than that of Taihu pigs at the age of 3 months(P＜0.01),But at age of 5 months,Taihu pigs had higher expression than Landrace(P＜0.05),there were not different between gender differences at the same age(P＞0.05).2.Development patterns of PPARGC1A mRNA expression were similar in backfat. They were decreased first and increased afterwards.For Taihu pigs,PPARGC1A gene expression was lowest at 2 months,and then continuously increased by 4 months,sharply declined at 5 months.For Landrace,PPARGC1A gene expression was lowest at 3 months, and then continuously increased by 5 months.The expression level of PPARGC1A mRNA in Taihu pigs was higher than that of Landrace at the age of 1 months(P＜0.05),and at age of 3 and 4 months,Taihu pigs had higher expression than Landrace(P＜0.01),there were not different between gender differences at the same age(P＞0.05).3.Expression level of PPARGC1A gene mRNA in ten different tissues from Landrace at the age of 6 months were analyzed.The abundance of PPARGC1A expression in Landrace from high to low was in the following order:kidney,liver,duodenum,intestinal lymph node,spleen,back fat,heart,quadriceps femoris,psoas major muscle and longissimus dorsi muscle.The expression level of PPARGC1A gene mRNA from kidney is the highest and very significantly higher than that of other tissues(P＜0.01).4.The relationship of PPARGC1A gene expression with carcass traits was different between the two breeds of pigs.For Landrace,PPARGC1A gene expression in longissimus dorsi muscle had negative relationship with backfat thickness,muscle fiber area and volume of adipocyte(P＜0.05);PPARGC1A gene expression in backfat had positive relationship with backfat thickness,muscle fiber area and volume of adipocyte,and the relevance reached a significant level(P＜0.05).For Taihu pigs,PPARGC1A gene expression in longissimus dorsi muscle had negative relationship with backfat thickness, muscle fiber area and volume of adipocyte,and the relevance of the former two reached a significant level(P＜0.05);PPARGC1A gene expression in backfat had positive relationship with backfat thickness,muscle fiber area and volume of adipocyte(P＞0.05).