The effect of chromosome substitution on endurance exercise capacity in inbred and F2 generation mice

Abstract

Previous research identified a region on chromosome 14 as an important regulator of endurance exercise capacity. The aim of this study was to identify the effect of chromosome substitution on endurance exercise capacity in inbred and hybrid mice. Mice from a chromosome substitution strain (CSS) derived from A/J (A) and C57Bl/6J (B6), denoted as B6.A14 were used to assess the contribution of chromosome 14 to endurance exercise capacity. To further investigate the heritability of the endurance exercise phenotype, 155 B6 x B6.A14 F2 mice were generated from a cross between B6 and B6.A14 CSS mice. All mice performed a graded exercise test to exhaustion to determine endurance exercise capacity. Endurance exercise capacity was expressed as time (min). B6 x B6.A14 F2 mice had an exercise capacity of 30.8 ± 0.1 minutes, which is significantly higher than parental B6.A14 CSS mice (28.5 ± 0.2 min) and similar to parental B6 mice (31.0 ± 0.1 min). Although the cohort mean is similar between F2 and B6 mice, the range of responses in the B6 x B6.A14 F2 mice (27.3 – 34.5 min) exceeded the range of the parental inbred strains. The range of responses in the B6 x B6.A14 F2 mice suggests that this population of mice is diverse in both phenotype and genotype and would be amenable to a chromosome‐wide scan for endurance exercise‐related genes.Supported by NIH grant HL085918 to MPM