Abstract

Viable mice homozygous for two recessive autosomal genes, hairless (hr) and obese (ob) were produced with an average life span of 538 ± 34.1 days. On the average, hairless-obese mice weighed about 73 percent as much as obese mice. Since obese mice consumed approximately 73 percent as much oxygen per gram body weight per hour as hairless-obese mice at about 24°C, the weight averages appear to be closely inversely related to the oxygen consumption averages. The presence or absence of pelage seems to make a negligible contribution to oxygen consumption in these two types of obese mice. The hairless condition of the hr/hr genotype seems to contribute to increased oxygen consumption beyond that expected as a consequence of their lower average body weight. The average oxygen consumptions for seven female mice in each of four phenotypic groups (hairless, normal, hairless-obese, and obese) were 3.87, 3.12, 2.39, and 1.74 ml/g/hr, respectively. The two mutants appear to interact in a simple additive way and not as a mutant suppression system. On an absolute basis, the hr/hr genotype seems to have approximately 54 percent as much affect on oxygen consumption as the ob/ob genotype. Litter records at about 60 days of age for four kinds of matings did not reveal any statistically significant deviations from expected ratios.

Disciplines

Biology

Publisher statement

Published by Oxford University Press. All rights reserved. The definitive version is available online at: http://jhered.oxfordjournals.org/cgi/content/abstract/72/6/395

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URL: http://digitalcommons.calpoly.edu/bio_fac/169