Open AccessElectron microscopic analysis of the banding pattern in the salivary gland chromosomes of Drosophila melanogaster : Divisions 23 through 26 of 2L
Author(s) -
SAURA ANJA O.
Publication year - 1980
Publication title -
hereditas
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.819
H-Index - 50
eISSN - 1601-5223
pISSN - 0018-0661
DOI - 10.1111/j.1601-5223.1980.tb01368.x
Subject(s) - biology , electron micrographs , chromosome , drosophila melanogaster , electron microscope , anatomy , karyotype , ultrastructure , evolutionary biology , genetics , optics , physics , gene
The banding pattern of squashed and thin‐sectioned salivary gland 2L chromosomes of Drosophila melanogaster has been studied with electron microscope (EM) and compared with the revised light microscopic (LM) map of P. N. Bridges. EM reveals a total of 173 bands in the chromosome divisions 23–26 , while there are 168 bands on the LM map. The most notable difference between electron micrographs and the LM map concerns the number of double bands. The EM analysis shows that only part of the doublets of the LM map retain the double appearance with EM. Many LM doublets are interpreted to be two separate singlets in EM. A few (6) bands drawn on the LM map cannot be seen at all with EM. Bands seen with EM only make up a further class of differences. There are as many as 24 very faint new bands in the chromosome region analyzed here. Furthermore, in one stock a prominent new band was seen in the region 25F . This new band can be accounted for by structural variation (i.e. as a probable duplication). In spite of these differences between EM and the LM map drawn by P. N. Bridges, the LM map depicts quite accurately the banding pattern within the region 25–26 of 2L.