Multiple amylase genes in Drosophila ananassae and related species.

The number and organization of amylase genes in Drosophila ananassae were investigated through classical genetic methods and in situ and filter hybridizations. At least four genes may be active in D. ananassae, organized as two independent pairs of closely linked copies on the 2L and 3L chromosomal arms. Several other species of the D. ananassae subgroup were studied and show the same chromosomal locations, suggesting an ancient duplication event. However, the number of Amy copies seems to be higher in the D. ananassae multigene family, and there is a striking intraspecific molecular differentiation.