Quantitative Trait Loci on Chromosomes 1 and 4 Affect Lipid Phenotypes in the Rat

The spontaneously hypertensive rat (SHR/Mol) and the spontaneously diabetic BB/OK rat were crossed, and the F1 hybrids were backcrossed onto the BB/OK rat in order to search for quantitative trait loci (QTL) affecting serum total cholesterol and triglycerides on chromosomes 1, 3, 4, 10, 13, 18, and X. On chromosome 4 a QTL for triglyceride levels (lod score 3.3) was found within the region flanked by theD4Mit9andIl-6markers. Suggestive linkage (lod score 1.9) was found for total cholesterol on chromosome 4 at theSprlocus. Also, on chromosome 1 suggestive linkage for both investigated traits was found at markerD1Mit14(lod score 1.9 for triglycerides, 2.1 for total cholesterol). The results of the study could contribute to the explanation of the genetic basis of lipid abnormalities, which are a common feature of pathological disorders such as coronary heart disease, hypertension, or non-insulin-dependent diabetes.