Hostname: page-component-586b7cd67f-tf8b9 Total loading time: 0 Render date: 2024-11-23T00:11:16.699Z Has data issue: false hasContentIssue false

Effects of X-rays on response to selection for a quantitative character of Drosophila melanogaster

Published online by Cambridge University Press:  14 April 2009

L. P. Jones
Affiliation:
Department of Animal Husbandry, University of Sydney, Sydney, Australia
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. Lines with ten pairs of parents and selected at an intensity of 20% were exposed to 1000 r. of X-rays for 0, 2, 10 or 30 generations.

Lines which received some irradiation generally gave greater response than the unirradiated controls. The phenotypic variance in the irradiated lines was much higher than in the controls. There was little difference in behaviour between lines receiving ten generations of irradiation and those irradiated every generation. Lines receiving only two generations of irradiation had lower variances than the other irradiated lines, but in one of three replicates the response was greater than the corresponding continuously irradiated line.

3. Lethal frequencies were much higher in irradiated than unirradiated lines. Particular chromosome II and III lethals were at high frequencies in most of the irradiated lines but in only two out of five controls.

4. On relaxation, the mean of the irradiated lines generally declined considerably, but in the unirradiated lines there was only a very small regression.

5. It appears that most of the extra response and increased variance in the irradiated lines were caused by a few genes with large effect on bristle number.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1967

References

REFERENCES

Brown, W. P. & Bell, A. E. (1961). Genetic analysis of plateaued lines of Drosophila melanogaster. Genetics, 46, 407425.CrossRefGoogle Scholar
Claringbold, P. J. & Barker, J. S. F. (1961). The estimation of relative fitness of Drosophila populations. J. Theoret. Biol. 1, 190203.CrossRefGoogle Scholar
Clayton, G. A. & Robertson, A. (1955). Mutation and quantitative variation. Am. Nat. 89, 151158.CrossRefGoogle Scholar
Clayton, G. A. & Robertson, A. (1964). The effects of X-rays on quantitative characters. Genet. Res. 5, 410422.CrossRefGoogle Scholar
Falconer, D. S. (1960). Introduction to Quantitative Genetics, p. 219, Table 12.2. Edinburgh: Oliver and Boyd.Google Scholar
Harrison, B. J. (1954). X-irradiation and selection. Drosoph. Inf. Serv. 28, 123124.Google Scholar
Latter, B. D. H. (1964). Selection for a threshold character in Drosophila. I. An analysis of the phenotypic variance on the underlying scale. Genet. Res. 5, 198210.CrossRefGoogle Scholar
Latter, B. D. H. (1965). The response to artificial selection due to autosomal genes of large effect. I. Change in gene frequency at an additive locus. Aust. J. biol. Sci. 18, 585598.CrossRefGoogle Scholar
Russell, W. L. (1956). Comparison of X-ray induced mutation rates in Drosophila and mice. Am. Nat. 90 (Suppl.), 6980.CrossRefGoogle Scholar
Scossiroli, R. E. (1953). Effectiveness of artificial selection under irradiation of plateaued populations of D. melanogaster. Proc. Symp. Genetics of Pop. Struct., Pavia, 4266.Google Scholar
Scossiroli, R. E. & Scossiroli, S. (1959). On the relative role of mutation and recombination in response to selection for polygenic traits in irradiated populations of D. melanogaster. Int. J. Radiat. Biol. 1, 6169.Google Scholar
Yamada, Y. (1961). Polygenic mutation rates for chaeta characters in Drosophila melanogaster. Jap. J. Genet. 36 (Suppl.), 7887.CrossRefGoogle Scholar
Yamada, Y. & Kitagawa, O. (1961). Doubling dose for polygenic mutations in D. melanogaster. Jap. J. Genet. 36, 7683.CrossRefGoogle Scholar