Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2000-7-26
pubmed:abstractText
DNA topoisomerase I (topo I) is an essential enzyme involved in replication, transcription, and recombination. To probe the functions of topo I during Drosophila development, we used top1-deficient flies with heat-shock-inducible top1 transgenes and were able to observe both zygotic and maternal functions of top1. A critical period for the zygotic function is in the late larval and early pupal stages. Topo I is required for larval growth and cell proliferation in imaginal disc tissues. The maternal functions consist of two aspects: oogenesis and early embryogenesis. During oogenesis, topo I is detected in the nuclei of early germ-line cells and follicle cells. The mutant ovary exhibits abnormal proliferation and defective nuclear morphology in these cells. There are extranumeral germ-line cells in individual egg chambers, while the follicle cells are underreplicated. Topo I is also stored maternally in early embryos. It localizes to the nuclei during interphase and prophase, but disperses into the cytoplasm at metaphase. Embryos from the mutant mother frequently show disrupted nuclear divisions with defects in chromosome condensation and segregation. The cytological and genetic analysis of the top1 mutant demonstrates that in Drosophila, topo I plays critical roles in many developmental stages active in cell proliferation.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0012-1606
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
222
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
27-40
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Essential functions of DNA topoisomerase I in Drosophila melanogaster.
pubmed:affiliation
Department of Biochemistry, Duke University Medical Center, Durham, North Carolina 27710, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.