Electron microscopic analysis of the banding pattern in the salivary gland chromosomes of Drosophila melanogaster Divisions 37, 38 and 39 of 2L

摘要

The electron microscope (EM) reveals 109 recognizable bands in the proximal divisions 37, 38 and 39 of the salivary gland chromosome 21. This number of bands is about 8% less than that given (119) on the revised light microscopic (LM) map of P. N. BRIDGES and again about 24% more than drawn by C. B. BRIDGES (88) on the original LM map for these divisions. The main difference between the banding patterns on the EM and the LM map is due to ten LM doublets that appear to be singlets in EM. Some LM singlets can not be seen at all in EM. There are, however, certain new bands visible with EM only. The correlation of boundary lines between the original and the revised LM map is discussed.