Similarity of centromeric heterochromatin in strains of drosophila melanogaster which interact to produce hybrid dysgenesis.

Many long-established laboratory strains of D. melanogaster interact with recently-collected wild-type strains, so that the progeny show sterility, enhanced mutation, male recombination and other degenerative traits, a syndrome known collectively as "hybrid dysgenesis". Tests have been made for differences in centromeric heterochromatin between interacting strains, by comparing homologues in mitotic preparations from hybrid individuals. Differences between homologues have not been revealed, either qualitatively by C-banding or quantitatively by in situ hybridisation to RNA transcripts from satellites 1.705 and 1.686. However, the sensitivities of the techniques are such that quantitative differences of less than 50% between strains could escape detection.