HMG1A and PPARG are differently expressed in the liver of fat and lean broilers

The expression of nine functional candidates for QT abdominal fat weight and relative abdominal fat content was investigated by real-time polymerase chain reaction (PCR) in the liver, adipose tissue, colon, muscle, pituitary gland and brain of broilers. The high mobility group AT-hook 1 (HMG1A) gene was up-regulated in liver with a ratio of means of 2.90 (P ≤ 0.01) in the "fatty" group (relative abdominal fat content 3.5 ± 0.18%, abdominal fat weight 35.4 ± 6.09 g) relative to the "lean" group (relative abdominal fat content 1.9 ± 0.56%, abdominal fat weight 19.2 ± 5.06 g). Expression of this gene was highly correlated with the relative abdominal fat content (0.70, P ≤ 0.01) and abdominal fat weight (0.70, P ≤ 0.01). The peroxisome proliferator-activated receptor gamma (PPARG) gene was also up-regulated in the liver with a ratio of means of 3.34 (P ≤ 0.01) in the "fatty" group relative to the "lean" group. Correlation of its expression was significant with both the relative abdominal fat content (0.55, P ≤ 0.05) and the abdominal fat weight (0.57, P ≤ 0.01). These data suggest that the HMG1A and PPARG genes were candidate genes for abdominal fat deposition in chickens. Searching of rSNPs in regulatory regions of the HMG1A and PPARG genes could provide a tool for gene-assisted selection.