Genetics, Vol 124, 627-636, Copyright © 1990

INVESTIGATIONS

Hybrid Dysgenesis-Induced Quantitative Variation on the X Chromosome of Drosophila melanogaster

C. Lai and TFC. Mackay
Department of Genetics, University of Edinburgh, Edinburgh EH9 3JN, Scotland

To determine the ability of the P-M hybrid dysgenesis system of Drosophila melanogaster to generate mutations affecting quantitative traits, X chromosome lines were constructed in which replicates of isogenic M and P strain X chromosomes were exposed to a dysgenic cross, a nondysgenic cross, or a control cross, and recovered in common autosomal backgrounds. Mutational heritabilities of abdominal and sternopleural bristle score were in general exceptionally high-of the same magnitude as heritabilities of these traits in natural populations. P strain chromosomes were eight times more mutable than M strain chromosomes, and dysgenic crosses three times more effective than nondysgenic crosses in inducing polygenic variation. However, mutational heritabilities of the bristle traits were appreciable for P strain chromosomes passed through one nondysgenic cross, and for M strain chromosomes backcrossed for seven generations to inbred P strain females, a result consistent with previous observations on mutations affecting quantitative traits arising from nondysgenic crosses. The new variation resulting from one generation of mutagenesis was caused by a few lines with large effects on bristle score, and all mutations reduced bristle number.

This article has been cited by other articles:

				C. Lai, R. McMahon, C. Young, T. F. C. Mackay, and C. H. Langley quemao, a Drosophila Bristle Locus, Encodes Geranylgeranyl Pyrophosphate Synthase Genetics, June 1, 1998; 149(2): 1051 - 1061. [Abstract] [Full Text] [PDF]