title: MDH-polymorphism in Drosophila subobscura: I. Selection and hitch-hiking in laboratory populations.
abstract: The interrelation of genic polymorphism at the Malate dehydrogenase (Mdh)-locus and chromosomal polymorphism for superimposed gene arrangements was studied in 5 experimental populations of Drosophila subobscura. It could be shown that chromosomal polymorphism is maintained by balancing selection in favour of the heterozygotes. In contrast, selection at the Mdh-locus itself seems to be of minor importance. The changes of frequency observed for the Mdh-alleles are most probably due to hitch-hiking on the gene blocks enclosed by the chromosomal structures or to selection for tightly linked genes rather than to fitness differences between Mdh-genotypes. The results may be considered as a model for the situation found in natural populations of D. subobscura.
authors.affiliation: Institut für Biologie II, Lehrstuhl Populationsgenetik, Universität Tübingen, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Pinsker