A Novel Polymorphism of VLDLR Signal Peptide Coding Region and Its Association with Growth and Abdominal Fat Traits of Gaoyou Domestic Ducks

ABSTRACT The VLDLR gene plays important roles in the growth and adiposity in humans and mice. The purpose of this study was to investigate the relationship between VLDLR gene genetic polymorphisms and growth and abdominal fat traits of the Gaoyou domestic duck. A total of 267 Gaoyou ducks were employed for testing. A 18bp deletion was identified in VLDLR signal peptide coding region. The results of c2 test suggested that the genotype frequencies of VLDLR signal peptide coding region were not in Hardy-Weinberg equilibrium. Least squares analysis showed that body weight (BW) of -18bp/-18bp genotype ducks was significantly higher than those of other genotypes from six (BW6) (p<0.05) to ten weeks of age (BW10) (p<0.01). The association analysis was performed taken body weight as covariant for abdominal percentage (AFP). Results showed that there was not interaction between genotype (p>0.05) and body weight for AFP and different genotypes had a significant effect on AFP (p<0.05). The results of Bonferroni t-test revealed that the abdominal fat percentage (AFP) of -18bp/-18bp genotype was significantly lower than those of +18bp/-18bp (p<0.05). Preliminary studies have shown that VLDLR may be a candidate gene for the selection for growth and abdominal fat, and the results of the present study indicate that VLDLR strongly influences carcass abdominal fat content of Gaoyou ducks.