Gender and age effects on the expression of genes related to lipid metabolism in broiler's liver

Two experiments were conducted to assess gender (Experiment 1) and age (Experiment 2) effects on the expression of genes related to lipid metabolism in broiler chickens. The expression of fatty acid synthase (FAS), apolipoprotein A-I (APOA-I), apolipoprotein B (APOB), adiponectin (ADIPOQ), liver kinase B1 (LKB1), and AMP-activated protein kinase α-1 (AMPKα-1) genes was evaluated by qRT-PCR. In Experiment 1, we observed a gender effect on feed intake, as male broilers presented greater feed intake than females. Female broilers presented greater gene expression of FAS, and lower expression of ADIPOQ and AMPKα-1, than males. A gender effect was not observed for the gene expression of APOA-I, APOB, or LKB1. In Experiment 2, there was a significant age effect on feed intake and weight gain. Broilers 42 days of age presented greater feed intake and weight gain than 21-day-old birds. 21-day-old broilers showed greater expression of APOA-I, ADIPOQ, LKB1, and AMPKα-1, and lower APOB gene expression in the liver than 42-day-old broilers. Age had no effect on FAS gene expression. Our results show that the gender and age could act on the expression of genes related to lipid synthesis, such as FAS and APOB, and also on genes related to lipid oxidation, such as ADIPOQ, LKB1, and AMPK.