Mitotic and polytene chromosomes of Drosophila nebulosa were subjected to C- and G-banding methods and to culture in a medium containing Hoechst 33258 in order to compare two types of centromeric heterochrornatln of chromosomes 2 ({3-heterochromatin) and X (a-heterochromatin). These types of heterochromatin did not differ in response to the various methods.The heterochromatin of the Y chromosome differed from that of the other chromosomes, reflecting peculiarities in its composition. The chromosomes of D. nebulosa were simpler and more homogeneous than those of other Drosophila species. The results agree with the phylogenetic position of D. nebulosa when compared with more complex chromosome patterns observed in phylogenetically higher Drosophila species which are more evolved in character. Ver menos