Linked Life Data

7649484

Source:http://linkedlifedata.com/resource/pubmed/id/7649484

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
16
pubmed:dateCreated
1995-9-28
pubmed:abstractText
Differentiation of the somatic macronucleus of ciliates after sexual events involves the programmed excision of thousands of single-copy internal eliminated sequences (IESs) from the germ-line genome. We have studied two cell lines of Paramecium tetraurelia that have identical germ-line genomes but differ in their macronuclear genomes. In the IES- cell line, a 222-bp IES interrupting a coding sequence is reproducibly excised during macronuclear differentiation, whereas it is not in the IES+ cell line. In a cross between the two lines, the developmental alternative in maternally inherited, suggesting that it is epigenetically controlled by the old (prezygotic) macronucleus in each cell. Transformation of the macronucleus of both lines with plasmids carrying fragments of either version of the gene shows that the presence of the IES sequence in the old macronucleus results in retention of the IES in the new macronuclear genome of sexual progeny. This could be attributable to (1) inhibition of excision, or (2) repair of a double-strand gap left in the genomic sequence after constitutive excision of the IES, by a polymerization mechanism using a homologous IES+ template from the old macronucleus. The latter possibility is ruled out by experiments showing that modified IESs can inhibit excision without being copied in the new macronuclear genome. Possible mechanisms are discussed in the light of a quantitative analysis of excision inhibition by the maternal IES sequence.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0890-9369
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
9
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2065-77
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Epigenetic self-regulation of developmental excision of an internal eliminated sequence on Paramecium tetraurelia.
pubmed:affiliation
Laboratoire de Génétique Moléculaire, URA1302, Ecole Normale Supérieure, Paris, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't