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Replicated selection for body weight in mice

Published online by Cambridge University Press:  14 April 2009

D. S. Falconer
D. S. Falconer
Affiliation:
Institute of Animal Genetics, Edinburgh, EH9 3JN
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The variation in the response to selection was studied by replication of selected lines. A random-bred strain of mice was divided into six replicates. Two-way selection for 6-week weight was applied in an identical manner to each replicate, and each had an unselected control. Each line (6 large, 6 control, 6 small) was maintained by minimal inbreeding with 8 single-pair matings. The overall mean responses, both up and down, were linear and very regular for ten generations, with realized heritabilities of 40% upwards, 33% downwards and 37% for the divergence. The separate replicates, however, differed greatly in their realized heritabilities, with upward selection ranging from 25 to 46%, and downward selection from 16 to 50%. The theoretical prediction that, because of genetic drift, the standard error of a realized heritability is underestimated by the standard error of the regression of response on cumulated selection differential was borne out in this experiment. The empirical standard error, calculated from the observed variance between replicates, was more than twice as great as that of the regression. The empirical standard errors showed that the asymmetry between upward and downward responses was not significant. The variation between the replicates was ascribed mainly to random drift, which may seriously influence the conclusions about the realized heritability and the asymmetry of response that would be drawn from a single experiment with the population size of one of these replicates. After 23 generations of selection the large lines were approaching limits, and the limit appeared to be at the same level in all. The small lines showed an undiminished realized heritability after 23 generations, but the selection differentials were then so small that little progress was made. There was evidence of counter-acting natural selection. All aspects of productivity – proportion of fertile matings, litter size and weaning rate – declined in the control lines. The overall productivity of the large lines was a little below the controls, and that of the small lines was reduced to about half the level of the controls. The separate replicates differed from each other significantly in all the components of productivity.

Type
Research Article
Information
Genetics Research , Volume 22 , Issue 3 , December 1973 , pp. 291 - 321
Copyright
Copyright © Cambridge University Press 1973

References

REFERENCES

Bohren, B. B., Hill, W. G. & Robertson, A. (1966). Some observations on asymmetrical correlated responses to selection. Genetical Research 7, 44–57.CrossRefGoogle ScholarPubMed
Bowman, J. C. & Falconer, D. S. (1960). Inbreeding depression and heterosis of litter size in mice. Genetical Research 1, 262–274.CrossRefGoogle Scholar
Dickerson, G. E. (1969). Techniques for research in quantitative animal genetics. In Techniques and Procedures in Animal Science Research, pp. 36–79. American Society of Animal Science.Google Scholar
Falconer, D. S. (1955). Patterns of response in selection experiments with mice. Cold Spring Harbor Symposia on Quantitative Biology 20, 178–196.CrossRefGoogle ScholarPubMed
Falconer, D. S. (1960 a). Selection of mice for growth on high and low planes of nutrition. Genetical Research 1, 91–113.CrossRefGoogle Scholar
Falconer, D. S. (1960 b). The genetics of litter size in mice. Journal of Cellular and Comparative Physiology 56 (Suppl. 1), 153–167.CrossRefGoogle Scholar
Falconer, D. S. (1965). Maternal effects and selection response. Proceedings XIth International Congress of Genetics 3, pp. 763–774.Google Scholar
Falconer, D. S. & King, J. W. B. (1953). A study of selection limits in the mouse. Journal of Genetics 51, 561–581.CrossRefGoogle Scholar
Falconer, D. S. & Robertson, A. (1956). Selection for environmental variability of body size in mice. Zeitschrift für Induktive Abstammungs- und Vererbungslehre 87, 385–391.Google ScholarPubMed
Hill, W. G. (1971). Design and efficiency of selection experiments for estimating genetic parameters. Biometrics 27, 293–311.CrossRefGoogle ScholarPubMed
Hill, W. G. (1972 a). Estimation of realised heritabilities from selection experiments. I. Divergent selection. Biometrics 28, 747–765.CrossRefGoogle ScholarPubMed
Hill, W. G. (1972 b). Estimation of realised heritabilities from selection experiments. II. Selection in one direction. Biometrics 28, 767–780.CrossRefGoogle ScholarPubMed
Monteiro, L. S. & Falconer, D. S. (1966). Compensatory growth and sexual maturity in mice. Animal Production 8, 179–192.Google Scholar
Roberts, R. C. (1966). The limits to artificial selection for body weight in the mouse. I. The limits attained in earlier experiments. Genetical Research 8, 347–360.CrossRefGoogle ScholarPubMed
Robertson, A. (1960). A theory of limits in artificial selection. Proceedings of the Royal Society B 153, 234–249.Google Scholar