Hostname: page-component-84b7d79bbc-g78kv Total loading time: 0 Render date: 2024-07-27T21:05:37.428Z Has data issue: false hasContentIssue false

The effects of inbreeding on the components of litter size in mice

Published online by Cambridge University Press:  14 April 2009

J. C. McCarthy
Affiliation:
Biology Department, Faculty of Agriculture, University College, Glasnevin, Dublin 9, Ireland

Extract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Twenty-four lines were bred from a base population of outbred Q mice by continued full-sib mating. Inbreeding depression in litter size at birth was observed. This decline in litter size was analysed in terms of ovulation rate, the incidence of preimplantation mortality and the incidence of postimplantation mortality. Pregnant females were dissected at 17½ days' gestation and the numbers of corpora lutea, or eggs, and of live and dead embryos were counted. Matings were arranged so that separate estimates of the effects of inbreeding in the mother and in the litter on the components of litter size could be obtained.

In the first generation of inbreeding when the inbreeding coefficient of the litter was raised from 0 to 25% decline in litter size was attributable to an increased incidence of preimplantation mortality.

In the second and fourth generations decline in litter size was attributable to (1) a reduction in the number of eggs ovulated by the inbred mothers, (2) an increased incidence of preimplantation mortality which resulted from inbreeding in the mother. No evidence of significant effects on mortality of inbreeding in the litter was obtained in the later generation of inbreeding.

These findings are discussed in the context of previous work on the effects of inbreeding and crossing on litter size and its components in mice and pigs.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1967

References

REFERENCES

Bowman, J. C. & Falconer, D. S. (1960). Inbreeding depression and heterosis of litter size in mice. Genet. Res. 1, 262274.CrossRefGoogle Scholar
Falconer, D. S. & Roberts, R. C. (1960). Effects of inbreeding on ovulation rate and foetal mortality in mice. Genet. Res. 1, 422430.CrossRefGoogle Scholar
King, J. W. B. & Young, G. B. (1957). Maternal influences on litter size in pigs. J. agric. Sci., Camb. 48, 457463.CrossRefGoogle Scholar
Lyon, M. F. (1959). Some evidence concerning the ‘mutational load’ in inbred strains of mice. Heredity, Lond. 13, 341352.CrossRefGoogle Scholar
McCarthy, J. C. (1965). The effect on litter size on crossing inbred strains of mice. Genetics, 51, 217222.CrossRefGoogle ScholarPubMed
Roberts, R. C. (1960). The effect on litter size of crossing lines of mice inbred without selection. Genet. Res. 1, 239252.CrossRefGoogle Scholar
Roberts, R. C. (1965). Some contributions of the laboratory mouse to animal breeding research. Anim. Breed. Abstr. 33, 515526.Google Scholar
Squiers, C. D., Dickerson, G. E. & Mayer, D. T. (1952). Influence of inbreeding, age and growth of sows on sexual maturity, rate of ovulation, fertilization and embryonic survival. Res. Bull. Mo. agric. Exp. Stn No. 494.Google Scholar