TABLE 1

Descriptive statistics for metabolic traits and body mass measured on outbred, genetically variable laboratory strain of house mice

TraitsNMeanSDMinMax
Basal metabolic rate (ml O2/hr)aFemale founderb9638.26.3112.555.5
Male founder2947.98.2732.668.2
Female offspring12235.57.1213.957.0
Male offspring12443.011.0611.877.0
Body mass (g) at start of BMR trialcFemale founder9621.632.23416.9228.11
Male founder2925.922.66821.0730.54
Female offspring12219.332.10914.8423.96
Male offspring12322.853.06414.9130.07
Avg. exercise Embedded Image (ml O2/hr)dFemale founder77237.635.89163.2316.4
Male founder22281.035.22220.0334.8
Female offspring118234.237.27169.1388.3
Male offspring122282.652.62198.9458.6
Embedded Image max (ml O2/hr)eFemale founder77237.635.89163.2316.4
Male founder22294.837.83231.2360.7
Female offspring118247.538.78180.2397.7
Male offspring123295.857.13203.0485.4
Avg. body mass (g) from exercise Embedded Image trialsfFemale founder7722.282.12217.5227.67
Male founder2227.652.78723.4132.62
Female offspring11821.651.79517.8626.59
Male offspring12226.922.91019.3134.80
  • a Food was removed from cages at about 1800 hr (CST) on the night prior to BMR determination; actual time was used as a covariate for analyses. Mean fast length (±SD) to start of BMR trial as 13.8 ± 0.68 (range 11.5–15.1) hours. Total fast length (±SD) to end of BMR trial was 23.8 ± 0.91 (range 20.6–25.7) hours.

  • b The term “founder” refers to measurements on breeder and nonbreeder males and females obtained from Harlan Sprague Dawley.

  • c Mean age (±SD) at BMR was 35.4 ± 2.57 (range 30–43) days.

  • d Reported exercise Embedded Image numbers were not corrected for washout characteristics of the metabolic chamber. Values for instantaneous corrected and steady-state Embedded Image values were similar (see text).

  • e One mouse died after the first trial.

  • f Mean age (±SD) at Embedded Image max was 41.9 ± 2.84 (range 37–49) days.