EVOLUTION OF A SMALL-MUSCLE POLYMORPHISM IN LINES OF HOUSE MICE SELECTED FOR HIGH ACTIVITY LEVELS

@inproceedings{GarlandJr2002EVOLUTIONOA,
  title={EVOLUTION OF A SMALL-MUSCLE POLYMORPHISM IN LINES OF HOUSE MICE SELECTED FOR HIGH ACTIVITY LEVELS},
  author={Theodore Garland Jr. and Martin T. Morgan and John G. Swallow and Justin S. Rhodes and Isabelle Girard and Jason G. Belter and Patrick A. Carter},
  year={2002}
}
Abstract To study the correlated evolution of locomotor behavior and exercise physiology, we conducted an artificial selection experiment. From the outbred Hsd:ICR strain of Mus domesticus, we began eight separate lines, each consisting of 10 breeding pairs. In four of the lines, we used within-family selection to increase voluntary wheel running. The remaining four lines were random-bred (within lines) to serve as controls. Various traits have been monitored to test for correlated responses… 

Selective Breeding and Short-Term Access to a Running Wheel Alter Stride Characteristics in House Mice

Postural and kinematic aspects of running may have evolved to support high runner (HR) mice to run approximately threefold farther than control mice. Mice from four replicate HR lines selectively

Glycogen storage and muscle glucose transporters (GLUT-4) of mice selectively bred for high voluntary wheel running

All mice showed some glycogen depletion during nightly wheel running, in muscles and/or liver, but the magnitude of this depletion was not large and hence does not seem to be limiting to the evolution of even-higher wheel running.

Endurance capacity of mice selectively bred for high voluntary wheel running

The HR lines had significantly higher endurance than the C lines, whether or not body mass was used as a covariate in the analysis, reinforcing previous studies that indicate sex-specific responses to selective breeding.

Selective breeding as a tool to probe skeletal response to high voluntary locomotor activity in mice.

A novel mouse-model based on selective breeding for high levels of voluntary wheel running is presented, and it is hypothesized that a reduction of myosin heavy-chain type-IIb isoforms with accounts for the observed ontogenetic changes in muscle mass.

Effects of activity, genetic selection and their interaction on muscle metabolic capacities and organ masses in mice

Organ morphology and biochemistry were altered in response to selective breeding for voluntary wheel running, chronic exercise and interactions as a result of ‘more pain, more gain’ or the evolution of greater phenotypic plasticity.

Shape‐shift: Semicircular canal morphology responds to selective breeding for increased locomotor activity

The findings suggest that semicircular canal morphology is responsive to evolutionary changes in locomotor behavior, but the pattern of response is potentially different in small‐ versus large‐bodied species.

Immune response to a Trichinella spiralis infection in house mice from lines selectively bred for high voluntary wheel running

Results complement those of previous studies suggesting decreased locomotor abilities during the chronic phase of T. spiralis infection, and despite reduced antibody production, breeding for high voluntary wheel exercise does not appear to have a substantial negative impact on general humoral function.

Mice selectively bred for high voluntary wheel running have larger midbrains: support for the mosaic model of brain evolution

This is the first example in which selection for a particular mammalian behavior has been shown to result in a change in size of a specific brain region, and it is hypothesized that the enlarged midbrain of HR mice is related to altered neurophysiological function in their dopaminergic system.

Do mice selectively bred for high locomotor activity have a greater reliance on lipids to power submaximal aerobic exercise ?

High-running mouse lines had whole-body fuel oxidation rates commensurate with maximal aerobic capacity, despite notable differences in skeletal muscle metabolic phenotypes.

Within-lifetime trade-offs but evolutionary freedom for hormonal and immunological traits: evidence from mice bred for high voluntary exercise

The results, and those of a previous study, suggest that selective breeding for high voluntary exercise has not altered immune function and suggest that the effects of evolved differences in baseline CORT levels may differ greatly from effects of environmental factors that alter baseline Cort during an individual’s lifetime.
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