Quantitative Genetics of Sprint Running Speed and Swimming Endurance in Laboratory House Mice (Mus domesticus)

Abstract

We tested the hypothesis that locomotor speed and endurance show a negative genetic correlation using a genetically variable laboratory strain of house mice (Hsd:ICR: Mus domesticus). A negative genetic correlation would qualify as an evolutionary "constraint," because both aspects of locomotor performance are generally expected to be under positive directional selection in wild populations. We also tested whether speed or endurance showed any genetic correlation with body mass. For all traits, residuals from multiple regression equations were computed to remove effects of possible confounding variables such as age at testing, measurement block, observer, and sex. Estimates of quantitative genetic parameters were then obtained using Shaw's (1987) restricted maximum-likelihood programs, modified to account for our breeding design, which incorporated cross-fostering. Both speed and endurance were measured on two consecutive trial days, and both were repeatable. We initially analyzed performances on each trial day and the maximal value. For endurance, the three estimates of narrow-sense heritabilities ranged from 0.17 to 0.33 (full ADCE model), and some were statistically significantly different from zero using likelihood ratio tests. The heritability estimate for sprint speed measured on trial day 1 was 0.17, but negative for all other measures. Moreover, the additive genetic covariance between speeds measured on the two days was near zero, indicating that the two measures are to some extent different traits. The additive genetic covariance between speed on trial day 1 and any of the four measures of endurance was negative, large, and always statistically significant. None of the measures of speed or endurance was significantly genetically correlated with body mass. Thus, we predict that artificial selection for increased locomotor speed in these mice would result in a decrease in endurance, but no change in body mass. Such experiments could lead to a better understanding of the physiological mechanisms leading to trade-offs in aspects of locomotor abilities.

Methods for estimating peak physiological performance and correlating performance measures

“…Lizards' minimum prey catching and handling time of five samples is found in Van Damme et al (1991). Similar studies with interest in maxima of repeated samples of individuals have been done with fish (Tudorache et al 2007), and rodents (Djawdan andGarland 1988 andDohm et al 1996).…”

Nonadditive Genetic Effects in Animal Behavior

“…Likewise, Gromko (1989) and Boake and Konigsberg (1998) reported negative heritabilities for courtship traits, although the estimates were not statistically significant. Nevertheless, Dohm et al (1996) found significant negative heritability estimates in some trials of house mouse sprint speed. For our housefly courtship traits, a model of genotype-by-environment interactions (where the environment is the mating partner; see Meffert 1995) can account for negative heritabilities.…”

Energy Cost of Wheel Running in House Mice: Implications for Coadaptation of Locomotion and Energy Budgets

“…Outbred, genetically variable Hsd:ICR mice (Hauschka and Mirand 1973;Dohm et al 1996;Carter et al 1999) were used to establish eight lines in 1993 (Swallow et al 1998a). In four of the lines, mice have been selected for high voluntary wheel running (measured at the age of 35 to 55 d as a total number of wheel revolutions per day); the other four have been randomly bred.…”

“…We have taken this approach with laboratory house mice (Mus domesticus) as a model system. Beginning from a base population of outbred Hsd:ICR mice (Hauschka and Mirand 1973;Dohm et al 1996), we have selected for increased levels of voluntary activity on running wheels (Swallow et al 1998a) and tested for correlated responses in various morphological and physiological traits (Swallow et al 1998b). …”