Linked Life Data

1803819

Source:http://linkedlifedata.com/resource/pubmed/id/1803819

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
1992-4-29
pubmed:abstractText
LC1, a YIP5-derived plasmid containing a human DNA fragment with ARS activity in yeast, has been used to study the replication of ARS plasmids in Saccharomyces cerevisiae. ARS plasmids carried in yeast hosts are normally mitotically unstable. In transformed cultures the fraction of cells that contain plasmid, measured by plating on selective media, is lower than would be expected from measured rates of plasmid loss. In the case of S. cerevisiae carrying either the plasmid LC1 or YRP17, the assay yields values of the order of 10-20% or 30-50% respectively. We have found that by doing a double nutritional upshift that involves conditioned medium and casamino acids, a population of cells can be defined that carry plasmid but are unable to grow on media that select for the plasmid marker. Thus the total fraction of cells that can be shown to contain plasmid increases to greater than 70%. To distinguish between the inability of plasmid to replicate in these cells and lack of expression of the selectable gene, cultures grown from single cells were analysed for the presence of plasmid DNA. In a substantial fraction of the population, plasmid DNA could be detected only by polymerase chain reaction and not by standard blotting and hybridization. These results suggest that plasmid is unable to replicate in these cells. Growth kinetics experiments with transformed cultures are consistent with the notion that only a small fraction of the cells contains plasmid capable of replication upon dilution into selective medium. Possible explanations for the phenomena observed are discussed.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0749-503X
pubmed:author
pubmed:issnType
Print
pubmed:volume
7
pubmed:geneSymbol
ARS1, URA3
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
943-52
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
On the level of plasmid-bearing cells in transformed cultures of Saccharomyces cerevisiae.
pubmed:affiliation
Dipartimento di Biologia Cellulare e dello Sviluppo, Universitá La Sapienza, Rome, Italy.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't