An attempt to detect genetic variation in sex ratio in Drosophila melanogaster

Two experiments were carried out in order to test for the existence of genetic variability in sex ratio in an outbred population of Drosophila melanogaster. In the first, the existence of heterogeneity in progeny sex ratio among dams and among sires was tested. No significant heterogeneity was detected. The heterogeneity variance component among sires was estimated to be only 4·4 × 10–6. In the second experiment, artificial family selection for increased and decreased proportions of males was practised for nine generations in each of two replicate lines. Selection was successful for decreased proportions, but this was shown to be due to the presence of sex-linked recessive lethals. There was no evidence for an increase in the proportion of males in the lines selected for increased proportions. The realised heritability of sex ratio was estimated as –0·0053, with an upper bound of 0·0033. It is concluded that genetic variation in sex ratio is effectively absent in this population. If this result were general it would cast doubt on the relevance of adaptative theories of primary sex ratio as far as diploid organisms are concerned. © 1982, The Genetical Society of Great Britain.

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Bibliographic Details
Main Authors: Toro, M. A., Charlesworth, B.
Format: journal article biblioteca
Language:eng
Published: 1982
Online Access:http://hdl.handle.net/20.500.12792/5522
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