Maternal-care behavior and life-history traits in house mice (Mus domesticus) artificially selected for high voluntary wheel-running activity

2002 ◽  
Vol 57 (1) ◽  
pp. 37-50 ◽  
Author(s):  
I Girard ◽  
J.G Swallow ◽  
P.A Carter ◽  
P Koteja ◽  
J.S Rhodes ◽  
...  
1999 ◽  
Vol 202 (18) ◽  
pp. 2513-2520 ◽  
Author(s):  
J.G. Swallow ◽  
P. Koteja ◽  
P.A. Carter ◽  
T. Garland

To test the hypothesis that body size and activity levels are negatively genetically correlated, we conducted an artificial selection experiment for increased voluntary wheel-running activity in house mice (Mus domesticus). Here, we compare body masses of mice from control and selected lines after 14 generations of selection. In both groups, beginning at weaning and then for 8 weeks, we housed half of the individuals with access to running wheels that were free to rotate and the other half with wheels that were locked to prevent rotation. Mice from selected lines were more active than controls at weaning (21 days) and across the experiment (total revolutions during last week: females 2.5-fold higher, males 2.1-fold higher). At weaning, mice from selected and control lines did not differ significantly in body mass. At 79 days of age, mice from selected lines weighed 13.6 % less than mice from control lines, whereas mice with access to free wheels weighed 4.5 % less than ‘sedentary’ individuals; both effects were statistically significant and additive. Within the free-wheel-access group, individual variation in body mass of males was negatively correlated with amount of wheel-running during the last week (P<0.01); for females, the relationship was also negative but not statistically significant (P>0.40). The narrow-sense genetic correlation between wheel-running and body mass after 8 weeks of wheel access was estimated to be −0. 50. A negative genetic correlation could account for the negative relationship between voluntary wheel-running and body mass that has been reported across 13 species of muroid rodents.


1985 ◽  
Vol 248 (2) ◽  
pp. R181-R189 ◽  
Author(s):  
J. L. Blank ◽  
C. Desjardins

The reproductive responses of two species of wild rodents, house mice and deer mice, were evaluated following a 30% reduction in food intake for 5 wk. These animal models were chosen as prototypes of other rodent species because each employs unique functional adjustments when confronted with reduced resources in their natural habitats. Modest inanition failed to alter pituitary-testicular function in house mice; neither spermatogenesis nor plasma concentrations of luteinizing hormone (LH) and testosterone were modified. In sharp distinction, deer mice exposed to restricted food intake showed significant reductions in plasma LH and testosterone and an accompanying loss in spermatogenesis. Reduced food intake also caused pronounced shifts in the temporal organization and amount of wheel-running activity in both animal models, albeit in a dichotomous fashion. House mice exhibited the same amount of wheel-running activity throughout inanition, but the diel periodicity of locomotor behavior was shifted from the dark to the light period. Deer mice, in comparison, significantly curtailed wheel-running activity during the dark hours but ran in precise phase relationship with the light-dark cycle. Taken together, our results establish that the male reproductive system and its supporting neuroendocrine and behavioral correlates can be disrupted by modest levels of food restriction in certain animal models.


2018 ◽  
Vol 124 (4) ◽  
pp. 923-929
Author(s):  
T. Seward ◽  
B. D. Harfmann ◽  
K. A. Esser ◽  
E. A. Schroder

Voluntary wheel cage assessment of mouse activity is commonly employed in exercise and behavioral research. Currently, no standardization for wheel cages exists resulting in an inability to compare results among data from different laboratories. The purpose of this study was to determine whether the distance run or average speed data differ depending on the use of two commonly used commercially available wheel cage systems. Two different wheel cages with structurally similar but functionally different wheels (electromechanical switch vs. magnetic switch) were compared side-by-side to measure wheel running data differences. Other variables, including enrichment and cage location, were also tested to assess potential impacts on the running wheel data. We found that cages with the electromechanical switch had greater inherent wheel resistance and consistently led to greater running distance per day and higher average running speed. Mice rapidly, within 1–2 days, adapted their running behavior to the type of experimental switch used, suggesting these running differences are more behavioral than due to intrinsic musculoskeletal, cardiovascular, or metabolic limits. The presence of enrichment or location of the cage had no detectable impact on voluntary wheel running. These results demonstrate that mice run differing amounts depending on the type of cage and switch mechanism used and thus investigators need to report wheel cage type/wheel resistance and use caution when interpreting distance/speed run across studies. NEW & NOTEWORTHY The results of this study highlight that mice will run different distances per day and average speed based on the inherent resistance present in the switch mechanism used to record data. Rapid changes in running behavior for the same mouse in the different cages demonstrate that a strong behavioral factor contributes to classic exercise outcomes in mice. Caution needs to be taken when interpreting mouse voluntary wheel running activity to include potential behavioral input and physiological parameters.


Evolution ◽  
2003 ◽  
Vol 57 (3) ◽  
pp. 646-657 ◽  
Author(s):  
Theodore J. Morgan ◽  
Theodore Garland ◽  
Patrick A. Carter

2001 ◽  
Vol 204 (24) ◽  
pp. 4311-4320 ◽  
Author(s):  
I. Girard ◽  
M. W. McAleer ◽  
J. S. Rhodes ◽  
T. Garland

SUMMARY In nature, many animals use intermittent rather than continuous locomotion. In laboratory studies, intermittent exercise regimens have been shown to increase endurance compared with continuous exercise. We hypothesized that increased intermittency has evolved in lines of house mice (Mus domesticus) that have been selectively bred for high voluntary wheel-running (wheel diameter 1.12 m) activity. After 23 generations, female mice from four replicate selection lines ran 2.7 times more revolutions per day than individuals from four random-bred control lines. To measure instantaneous running speeds and to quantify intermittency, we videotaped mice (N=41) during a 5-min period of peak activity on night 6 of a 6-day exposure to wheels. Compared with controls (20 revs min–1 while actually running), selection-line females (41 revs min–1) ran significantly faster. These instantaneous speeds closely matched the computer-recorded speeds over the same 5-min period. Selection-line females also ran more intermittently, with shorter (10.0 s bout–1) and more frequent (7.8 bouts min–1) bouts than controls (16.8 s bout–1, 3.4 bouts min–1). Inter-bout pauses were also significantly shorter in selection-line (2.7 s) than in control-line (7.4 s) females. We hypothesize that intermittency of locomotion is a key feature allowing the increased wheel-running performance at high running speeds in selection-line mice.


2017 ◽  
Vol 124 (1) ◽  
pp. 346-355 ◽  
Author(s):  
Ryan A. Whitehead ◽  
Nicholas L. Lam ◽  
Melody S. Sun ◽  
Joshua Sanchez ◽  
Shahani Noor ◽  
...  

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