title: Influence of genetic background on daily running-wheel activity differs with aging.
abstract: In humans, physical activity declines with age. We tested the hypothesis that genetic background and age interact to determine daily wheel-running physical activity patterns in mice. Five female mice from ten inbred strains (A/J, AKR/J, Balb/cJ, CBA/J, C3H/HeJ, C3Heb/FeJ, C57Bl/6J, C57L/J, DBA/2J, and SWR/J) were studied for 26 wk starting at 10 wk of age. All mice were housed in separate cages, each with a running wheel and magnetic sensor. Throughout the 26-wk period, age-related change in daily duration (P < 0.0001), daily distance (P < 0.0001), and average velocity (P = 0.0003) differed between the inbred strains. Unlike the other strains, SWR/J mice increased their running-wheel activity throughout the 6-mo time period. Broad-sense heritability estimations for the strains across the 26-wk period ranged between 0.410 and 0.855 for the three physical activity phenotypes. Furthermore, the broad-sense heritability estimates for daily running-wheel distance differed across time and suggested an interaction between genetic background and age on physical activity in these inbred mice.
authors.affiliation: Department of Kinesiology, University of North Carolina-Charlotte, Charlotte 28223, USA. miturner@uncc.edu
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Turner
authors.forename: Steven R
authors.initials: SR
authors.lastname: Kleeberger
authors.forename: J Timothy
authors.initials: JT
authors.lastname: Lightfoot
mesh_terms: D000375:Aging / Q000235:genetics / Q000502:physiology*; D000818:Animals; D001835:Body Weight / Q000235:genetics; D005260:Female; D051379:Mice; D008815:Mice, Inbred Strains; D009043:Motor Activity / Q000235:genetics* / Q000502:physiology*; D013997:Time Factors