Abstract: Three groups of chickens were fed to study the differences of phenotypic values and mRNA expression of genes associated with fat deposition in the divergent-selected chicken lines. The IMF divergent-selected lines and unselected Beijing You chicken were fed and slaughtered at day 56 and 120. The phenotypic values of IMF content, abdominal fat weight, abdominal fat proportion and mRNA expression of LPL, H-FABP and A-FABP genes were measured and compared among groups. The results showed that IMF content and L* value of chicken muscle in upselected line (UL) was higher than the down-selected line (DL) at both day of 56 and 120, but the ultimate pH of breast muscle was lower. The differences were significant (P<0.05). At day of 120, the LPL in abdominal fat of UL expressed more than DL significantly (P<0.05), but the H-FABP in breast muscle expressed less significantly (P<0.05).

Key words: chicken, IMF divergent-selected line, IMF, mRNA expression