The International Complex Trait Consortium

A Genome Scan For Quantitative Trait Loci (QTLs)
Associated With Aerobic Running Capacity In Rats

Lauren Gerard Koch, Justin A. Ways, George T. Cicila, Michael R. Garrett, Steven L. Britton

Functional Genomics Laboratory, Medical College of Ohio, Toledo, OH 43614

The divide between health and disease is fundamentally defined within variation for aerobic capacity. From a panel of inbred strains, we identified Copenhagen (COP) and DA rats to be most divergent (145%) for a test of aerobic treadmill running. An F2(COPxDA) intercross population (n=224 males) was used to identify QTLs for aerobic running capacity. Selective genotyping was done on F2(COPxDA) extremes (n=90) with 210 polymorphic microsatellite markers spaced 10-20cM apart. MapManagerQTX detected QTL associations (LOD scores>1.85) on chromosomes 3, 7, 8, 16 and 20. Genotyping was completed on the entire F2(COPxDA) population for these potential loci. Aerobic running capacity QTLs were re-established for chromosomes 3 and 16. "Suggestive" linkage (LOD=2.2) was observed near the p-terminus of Chr. 3 between D3Rat56 and D3Rat277.

The LOD plot on Chr. 16 revealed two peaks separated by more than 30 cM: D16Rat17 showed "significant" linkage (LOD=4.0), and D16Rat55 was "suggestive" (LOD=2.9). All three QTLs showed a dominant mode of inheritance where the presence of at least one DA-allele was associated with greater distance run, compared to rats homozygous for the COP-allele.

[Supported by NIH HL64270] Next Abstract: Genetic Models Of Aerobic Endurance Running Capacity In Rats