Detection of QTL for body weight and body fat content in mice using genetic markers

The aim of the project was the identification of quantitative trait loci (QTL) for body weight and body fat content. Using selected (Du6, Du6P) and randomly mated (DuKs) mouse lines with differences in body weight and abdominal fat content up to 100%, the study was carried out in three steps: (1) Line specific alleles were detected for DNA fingerprint banding patterns and equally spaced microsatellite markers. (2) Linkage analysis was performed In informative families generated by crosses between the lines to prove if the line specific allele distribution at single loci is the result of the selection process. The Maximum Likelihood test statistic (MLS) provided evidence for a QTL effecting growth on chromosome 11 (MLS=7.6). A QTL responsible for abdominal fat content may be suggested on chromosome 3 (MLS=2.7). (3) Expression analysis of the putative candidate genes Gh and Ap2 in the chromosomal regions with effect on the trait differentiation revealed no differences between the lines. Differences in the tissue specific gene expression levels between the lines were detected for the Gpd and the Igf1-genes.