Linked Life Data

9847243

Source:http://linkedlifedata.com/resource/pubmed/id/9847243

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1999-3-8
pubmed:abstractText
Polytene chromosomes exhibit intricate higher order chromatin structure that is easily visualized due to their precisely aligned component strands. However, it remains unclear if the same factors determine chromatin organization in polyploid and diploid cells. We have analyzed one such factor, the cell cycle, by studying changes in Drosophila nurse cell chromosomes throughout the 10 to 12 endocycles of oogenesis. We find that nurse cells undergo three distinct types of endocycle whose parameters are correlated with chromosome behavior. The first four endocycles support complete DNA replication; poorly banded polytene euchromatin progressively condenses during the late S phases to produce blob-like chromosomes. During the unique fifth endocycle, an incomplete late S phase is followed by a mitosis-like state during which the 64C chromosomes dissociate into 32 chromatid pairs held together by unreplicated regions. All the subsequent endocycles lack any late S phase; during these cycles a new polytene chromosome grows from each 2C chromatid pair to generate 32-ploid polytene nuclei. These observations suggest that euchromatin begins to condense during late S phase and that nurse cell polytene chromosome structure is controlled by regulating whether events characteristic of late S and M phase are incorporated or skipped within a given endocycle.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0950-1991
pubmed:author
pubmed:issnType
Print
pubmed:volume
126
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
293-303
pubmed:dateRevised
2009-9-28
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
The endocycle controls nurse cell polytene chromosome structure during Drosophila oogenesis.
pubmed:affiliation
Howard Hughes Medical Institute, Carnegie Institution of Washington, Department of Embryology, Baltimore, MD 21210, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.