Inbreeding effects on physiological responses to chronic hypoxia in mice (Mus musculus)

UNCW Author/Contributor (non-UNCW co-authors, if there are any, appear on document)
Jennifer Irene Berting (Creator)
The University of North Carolina Wilmington (UNCW )
Web Site:
Wade Watanabe

Abstract: Changes in complex phenotypes, such as exercise tolerance, are often mediated by the co-adjustment of many components. For example, hypoxic exercise tolerance (HET) is typically enhanced by the myriad physiological adjustments that accompany acclimation to hypoxia. Further, exercise tolerance is strongly influenced by genetic background, but the effect of genetic variation is largely unknown. The present study sought to examine the consequence of reduced genetic variation, in the context of inbreeding, and its effect on the relationship between hypoxic exercise tolerance (HET), maximal aerobic capacity (VO2max), and myoglobin concentration ([Mb]) in Mus musculus. I hypothesized that the increased homozygosity found in inbred strains would lead to reduced phenotypic plasticity, resulting in more variable responses to chronic hypoxia. In addition, I hypothesized that HET and VO2max would be positively correlated. Hypoxia led to decreases in body mass as well as increases in HET and hypoxic VO2max in all strains. While there was no significant effect of breeding on HET, the change in VO2max and the cost of exercise following hypoxic acclimation were greater among inbred than outbred strains. The response of [Mb] to hypoxia was generally greater among inbred than outbred strains as predicted, but the differences were mostly non-significant. HET and VO2max were positively correlated, but [Mb] was not correlated with either of these variables. The consistent influence of inbreeding on body mass, VO2max, and cost of exercise suggest an underlying consequence of genetic uniformity. While there was some support for the hypothesis that reduced phenotypic plasticity in inbred strains leads to a more variable response to hypoxia, on the whole the results were not consistent with this view.

Additional Information

A Thesis Submitted to the University of North Carolina at Wilmington in Partial Fulfillment of the Requirement for the Degree of Masters of Science
Language: English
Date: 2009
Mice as laboratory animals, Mice--Research
Mice -- Research
Mice as laboratory animals

Email this document to