Genetic analysis and epistatic interaction association of lipid traits in a C57xBalb/c F2 mice

Abstract The quantitative trait loci (QTL) controlling lipid traits were studied using microsatellite markers in mice at two different stages of life i.e. at 12 and 28 weeks. Additionally, the epistatic interactions between QTLs were also evaluated. One significant QTL for cholesterol (Tcholq1, logarithm of odds ratio, LOD: 3.49) on chromosome 2 and two QTL for low density lipoprotein, Ldlq1 & Ldlq2 were identified on chromosome 2 and 10 with LOD value of 5.43 and 3.39 respectively. However, suggestive QTL for cholesterol was identified on chromosome 1, 2, 9 & 13, for high density lipoprotein (HDL) on chromosome 2 &7 and for triglycerides on chromosome 11 & 14. The QTL identified for LDL on chromosome 2 near marker D2Mit75 showed the pleiotropic effect with cholesterol and HDL trait in mice. The epistatic analysis among all interacting loci for all lipid traits revealed 51 significant digenetic interactions (LOD˃5.0) of which the maximum was recorded for LDL at 12 weeks, however 63 interactions were identified at 28 weeks with a maximum for cholesterol. The study suggests that these lipid traits are governed through a complex genomic interactions and these interactions are different at different stage of life.