|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | |||||
First published online 29 January 2003
doi: 10.1242/jcs.00283
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Research Article |
1 Department of Cytology and Genetics, Novosibirsk State University, Novosibirsk
630090, Russia
2 Department of Cytology and Genetics, Novosibirsk 630090, Russia
* Author for correspondence (e-mail: zhimulev{at}bionet.nsc.ru)
Accepted 19 November 2002
Heterochromatic DNA sequences in the polytene chromosomes of Drosophila melanogaster salivary glands are under-replicated in wild-type strains. In salivary glands of SuUR and in the nurse cells of otu mutants, under-replication is partly suppressed and a banded structure appears within the centric heterochromatin of chromosome 3. This novel banded structure in salivary gland chromosomes was called Plato Atlantis. In order to characterize the heterochromatic component of Plato Atlantis, we constructed a fine-scale cytogenetic map of deletions with break points within centric heterochromatin (Df(3L)1-16, Df(3L)2-66, Df(3R)10-65, Df(3R)4-75 and Df(3L)6B-29 + Df(3R)6B-29). Salivary gland chromosomes show that Df(3L)1-16 removes the complete Plato Atlantis, while Df(3L)2-66 deletes the most proximal 3L regions. These deletions therefore show a substantial cytological overlap. However, in the chromosomes of nurse cells, the same deficiencies remove distinct heterochromatic blocks, with the region of overlap being almost invisible. Satellite (AATAACATAG, AAGAG) and dodecasatellite DNAs mapped in a narrow interval in salivary glands but were found in three clearly distinguishable blocks in nurse cells. The 1.688 satellite was found at a single site in salivary glands but at two sites in nurse cells. We show that newly polytenized heterochromatic structures include blocks h47-h50d of mitotic heterochromatin in salivary glands, but the additional blocks h50p, h53 and h57 are also included in nurse cell chromosomes. Tissue specificity of the patterns of abnormal heterochromatic polytenization implies differential control of DNA replication in somatic and germline cells.
Key words: Heterochromatin, Polytenization, Chromosome 3, Drosophila melanogaster
![]()
CiteULike
Complore
Connotea
Del.icio.us
Digg
Reddit
Technorati
Twitter What's this?
This article has been cited by other articles:
![]() |
E. N. Andreyeva, T. D. Kolesnikova, O. V. Demakova, M. Mendez-Lago, G. V. Pokholkova, E. S. Belyaeva, F. Rossi, P. Dimitri, A. Villasante, and I. F. Zhimulev High-resolution analysis of Drosophila heterochromatin organization using SuUR Su(var)3-9 double mutants PNAS, July 31, 2007; 104(31): 12819 - 12824. [Abstract] [Full Text] [PDF] |
||||
![]() |
O. V. Demakova, G. V. Pokholkova, T. D. Kolesnikova, S. A. Demakov, E. N. Andreyeva, E. S. Belyaeva, and I. F. Zhimulev The SU(VAR)3-9/HP1 Complex Differentially Regulates the Compaction State and Degree of Underreplication of X Chromosome Pericentric Heterochromatin in Drosophila melanogaster Genetics, February 1, 2007; 175(2): 609 - 620. [Abstract] [Full Text] [PDF] |
||||