Polytene chromosome arrangements in Drosophila bocki.

Cytological investigations of salivary gland polytene chromosomes of the Drosophila kikkawai complex in Thailand have revealed an interesting pattern of species divergence. Drosophila bocki, D. leontia and D. kikkawai share chromosome arrangement 3LB. However, additional gene arrangements of 3LA and 3LC have been observed in D. kikkawai and D. leontia, respectively, while D. bocki remains polymorphic for inversion 3LB. Chromosomal evidence seems to suggest that D. bocki is similar to a common ancestor of the D. kikkawai complex.