Interstrain variation in murine aerobic capacity.
OBJECTIVE
The contribution of genetic factors to aerobic capacity is unknown. The purpose of this study was to measure maximal aerobic performance among inbred strains of mice to provide basic heritability estimates.


METHODS
Eight female mice, 8 to 10 wk old, in 10 inbred strains (A/J, AKR/J, Balb/cJ, C(3)H/HeJ, C57Bl/6J, C57L/J, C(3)Heb/FeJ, CBA/J, DBA/2J, and SWR/J) were run on a treadmill until exhaustion. The protocol started at 22 m.min(-1) and increased in speed approximately 6 m.min(-1) every 4 min. After 4 min at 42.4 m.min(-1), the grade was increased 2% every 4 min thereafter until the mouse could not run off of the shock grid (150 V; 1.5 mA).


RESULTS
There were significant differences between inbred strains in maximal duration of exercise accomplished (P < 0.0001). The order of strain-specific exercise duration was Balb/cJ > SWR/J > CBA/J > C57L/J > C3H/HeJ > C3Heb/FeJ > C57Bl/6J > AKR/J > DBA/2J > A/J. Two measures of heritability in the broad sense, intraclass correlation (0.73), and the coefficient of genetic determination (0.58) were both significant.


CONCLUSIONS
These data indicate that there is a strong genetic contribution to aerobic capacity in mice.
Lightfoot
J T
JT
Department of Health Promotion and Kinesiology, University of North Carolina-Charlotte, Charlotte, NC 28223, USA. jtlightf@email.uncc.edu
Turner
M J
MJ
Debate
K A
KA
Kleeberger
S R
SR
D000818:Animals; D001835:Body Weight; D005260:Female; D051379:Mice; D008805:Mice, Inbred A / Q000235:genetics / Q000502:physiology; D008806:Mice, Inbred AKR / Q000235:genetics / Q000502:physiology; D008807:Mice, Inbred BALB C / Q000235:genetics / Q000502:physiology; D008809:Mice, Inbred C3H / Q000235:genetics / Q000502:physiology; D008810:Mice, Inbred C57BL / Q000235:genetics / Q000502:physiology; D008808:Mice, Inbred CBA / Q000235:genetics / Q000502:physiology; D008811:Mice, Inbred DBA / Q000235:genetics / Q000502:physiology; D008815:Mice, Inbred Strains / Q000235:genetics* / Q000502:physiology*; D010805:Physical Conditioning, Animal / Q000502:physiology*; D010807:Physical Endurance / Q000502:physiology*; D012119:Respiration / Q000235:genetics*; D013045:Species Specificity