Differentiation of four taxa of the Anopheles balabacensis complex using H-banding patterns in the sex chromosomes
Analyses of metaphase chromosomes of four taxa of the Anopheles balabacensis complex (A. dirus A, B, and C, and A. takasagoensis) using the Hoechst 33258 staining technique have revealed remarkable differences in the fluorescence banding patterns of the sex chromosomes. These result from changes in the amount and distribution of constitutive heterochromatin. This evidence supports the results from cross-mating experiments and from morphological studies which indicate that three of these taxa, A. takasagoensis, dirus A, and dirus B, are sibling species. Differences in H-staining patterns of the sex chromosomes of a dirus colony from Kanchanaburi suggest that it too is a genetically distinct taxon, provisionally designated as dirus C, within the A. balabacensis complex.Key words: Anopheles, H-banding, heterochromatin, sex chromosomes.