Hybrid Dysgenesis in Drosophila Melanogaster: A Possible Explanation in Terms of Spatial Organization of Chromosomes

Abstract

Male.recombination and female sterility, two aspects of hybrid dysgenesis in D. melanogaster, have been studied in crosses between a locally collected wild population and laboratory strains. Dysgenesis occurs in the Fl hybrid of such crosses only if the wild type is used as maie parent and the laboratory strain as female, suggesting an interaction between genotype and cytoplasm. However the results from further crosses are difficult to interpret in terms of a conventional genotype--cytoplasm model, and suggest that for dysgenesis to occur it is necessary-that the wild-type chromosomes be contributed by the male parent. Furthermore, receipt of any of the three major wild-type chromosomes in crosses to laboratory females is sufficient to cause hybrid dysgenesis.