Characterization and modification of heterochromatin in four species of the immigrans species group of Drosophila

Abstract

The distribution of constitutive heterochromatin in mitotic chromosomes of four species (viz., Drosophila quadrilineata de Meijere, D. immigrans Sturtevant, D. pulaua Wheeler, and D. kohkoa Wheeler) was studied using C-banding and fluorescence staining techniques. The results of this study had revealed that the heterochromatic segments detected by C-banding in the species under study were found to coincide precisely with the areas giving bright fluorescence with the two fluorochromes, Hoechst 33258 and quinacrine. This suggested the presence of A–T rich base pairs in their heterochromatin. These studies further revealed that the modification of heterochromatin caused due to the additions or deletions in particular had also played a very significant role during the differentiation of these species.Key words: heterochromatin modification, immigrans species group, Drosophila.