Changes in peroxisome proliferator-activated receptor gamma gene expression of chicken abdominal adipose tissue with different age, sex and genotype

Peroxisome proliferatior-activated receptor gamma (PPARγ) is a transcription factor that regulates adipocyte differentiation, and the activation of PPARγ increases fat deposition in growing chickens. The aim of the present study was to investigate whether the levels of PPARγ gene expression were related to fat pad weight in abdominal adipose tissue in growing chickens with different genotype and sex. Body weight and abdominal adipose tissue weight in broiler chickens (Ross strain) were higher than the other genotypes (Road Island Red, White Leghorn, and Japanese native poultry (Tsushima)) at 3 and 5 weeks of age. PPARγ mRNA expression in abdominal adipose tissue tended to increase with age, as evidenced by higher expression levels at 5 weeks than at 1 week of age in all sex and genotype of chickens. In broiler chickens, the PPARγ expressions were significantly higher than the other genotypes. PPARγ mRNA expression levels in abdominal adipose tissue of female chickens rapidly increased at 3 weeks, and were unchanged until 5 weeks, while those in male chickens gradually increased until 5 weeks. In addition, abdominal adipose tissue weight was correlated with PPARγ expression levels. These results demonstrated that PPARγ gene expression is a useful marker of fat deposition in chickens, suggesting that PPARγ is a key factor of fat accumulation in chicken abdominal fat pad.