Electron microscopic analysis of the E polytene chromosome of Drosophila subobscura: divisions 57, 58 and 59

Abstract

The banding pattern of the divisions 57, 58 and 59 of the E polytene chromosome of Drosophila subobscura was analyzed by electron microscopy. Using squashed and thin-sectioned polytene chromosomes, our electron microscopic results have been compared with the reference map of Kunze-Müller (Chromosoma 9, 559-570 (1958]. These divisions are rich in heavy bands, and their number and location coincide with those of the reference map. The major differences observed between our electron micrographs and the reference map have been at the level of faint bands.