Heat shock genes in the willistoni group of Drosophila: induced puffs and proteins.

Seven species of the willistoni group of Drosophila were comparatively analysed for their response to heat shock and anoxia, both at the transcriptional (induced puff) and translational (induced protein) levels. The number of induced puffs varied among the species, but were concentrated at chromosomes 3 and XR. One puff present under control (25 degrees C) conditions was found to increase in size in response to stress in all species. Proteins of 83 and 70 kD were induced in all species in response to heat shock, as well as proteins of 50 and 32 kD, but not reported for other species of Drosophila under similar conditions. The number and size of the small heat shock proteins induced, as expected, showed considerable interspecific variability.