Hostname: page-component-586b7cd67f-r5fsc Total loading time: 0 Render date: 2024-11-28T00:11:55.821Z Has data issue: false hasContentIssue false
  • English
  • Français

The effects on litter size of crossing lines of mice inbred without selection

Published online by Cambridge University Press:  14 April 2009

R. C. Roberts
R. C. Roberts
Affiliation:
Agricultural Research Council Unit of Animal Genetics, Institute of Animal Genetics, Edinburgh 9
Rights & Permissions [Opens in a new window]

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.

1. The experiment was designed to provide basic information relevant to the utilization of heterosis in animal improvement. The character studied was the size of the first litter in mice.

2. Thirty inbred lines were crossed at random when the inbreeding coefficient reached 0·50 (three full-sib matings). The lines had been inbred without selection except for natural selection operating with lines.

3. The mean litter size of the crossbred mice did not exceed that of the outbred population from which the inbred lines had been derived. This indicates that the increased litter size normally associated with crossbred mice must be ascribed to some form of selection other than within-line natural selection.

4. Estimates were obtained of the variance components associated with general and special combining abilities. As anticipated, these estimates were very small, especially those relating to special combining ability. Before selection between crosses becomes possible, high levels of inbreeding must be achieved.

Type
Research Article
Information
Genetics Research , Volume 1 , Issue 2 , July 1960 , pp. 239 - 252
Copyright
Copyright © Cambridge University Press 1960

References

REFERENCES

Bowman, J. C. and Falconer, D. S. (1960). Inbreeding depression and heterosis of litter size in mice. Genet. Res. 1, 262–274.CrossRefGoogle Scholar
Donald, H. P. (1955). Controlled heterozygosity in livestock. Proc. Roy. Soc. B, 144, No. 915, 192–203.Google ScholarPubMed
Eaton, O. N. (1953). Heterosis in the performance of mice. Genetics, 38, 609–629.CrossRefGoogle ScholarPubMed
Falconer, D. S. (1955). Patterns of response in selection experiments with mice. Cold Spring Harbor Symp. Quant. Biol. 20, 178–196.CrossRefGoogle ScholarPubMed
Henderson, C. R. (1953). Estimation of variance and covariance components. Biometries 9, 226–252.CrossRefGoogle Scholar
Mather, K. (1949). Biometrical Genetics. London: Methuen.Google Scholar
Robertson, A. (1952). The effect of inbreeding on the variation due to recessive genes. Genetics, 37, 189–207.CrossRefGoogle ScholarPubMed