A mutation in the chicken lipoprotein lipase gene is associated with adipose traits

Abstract

Lipoprotein lipase (LPL), which consists of an N-terminal catalytic domain and a C-terminal binding domain, is a crucial enzyme in the metabolism of lipids. Binding in the presence of cofactors or receptors on the cell surface, LPL catalyses the hydrolysis of triglycerides in the lipoprotein. To investigate the correlation between the LPL gene and adipose traits, single nucleotide polymorphisms in the exons of LPL in two breeds, Tibet chicken and E-white recessive rock (EWRR) chicken were investigated. The two breeds have significantly different levels of obesity. They were screened with single-strand conformation polymorphism and its effect on adipose traits was analysed. The results showed that a missense mutation G–C in the seventh exon of LPL changed alanine 377 to proline at the C-terminal binding domain, which is involved in the binding activity of LPL. Association analysis showed that the intermuscular adipose tissue width of Tibet chicken with the CC genotype decreased significantly (P < 0.05), while abdominal adipose weight of EWRR chicken of the CC genotype increased markedly (P < 0.05) compared with the individuals of other genotypes. Although the mutation correlated with very low-density lipoprotein in Tibet chicken, it did not demonstrate significant association with the lipoprotein in EWRR chicken (P > 0.05). Neither the glucose or triglyceride levels of chickens with different genotypes differed significantly (P > 0.05). As very low-density lipoprotein content and fat mass were upregulated by LPL, we concluded that the A377P mutation may enhance the binding activity of the LPL C-terminal domain to very low-density lipoprotein receptors, which promoted triglyceride metabolism in very low-density lipoprotein.