Meeting Abstract

73.1  Sunday, Jan. 6  Heritability and genetic trends for metabolic traits in laboratory mice WONE, B.*; SEARS, M/W; LABOCHA, M/K; DONOVAN, E/R; HAYES, J/P; University of Nevada, Reno; Southern Illinois University, Carbondale; University of Nevada, Reno; University of Nevada, Reno; University of Nevada, Reno woneb@unr.edu

The aerobic capacity model posits that resting metabolism (BMR) and aerobic capacity (VO₂ max) are intrinsically linked features of vertebrate organismal design and that endothermy evolved because natural selection for high aerobic capacity led to a correlated increase in BMR. To explore the aerobic capacity model, we are conducting an artificial selection experiment on BMR and VO₂ max of Mus musculus. The selection regimes are: (1) control, (2) directional selection for high mass-independent VO₂ max, and (3) correlational selection for a negative correlation between mass-independent BMR and VO₂ max. We used an animal model approach to estimate genetic variances and covariances and trends in breeding values of BMR and VO₂ max. Preliminary results based on data from the first three generation of selection indicate the following. Narrow-sense heritability (h²) was ~ 0.3 for mass-independent BMR and ~ 0.5 for mass-independent VO₂ max. Phenotypic and genetic correlations between mass-independent traits were low and positive. We detected a positive genetic trend for mass-independent VO₂ max in the directional and correlational selection lines. In addition, we detected a negative genetic trend for mass-independent BMR in the correlational line. Our results suggest that it will be possible to engineer mice with significantly different mass-independent BMR and VO₂ max and that it may be possible to alter the correlation between these variables by artificial selection. Supported by NSF IOS 0344994.