Linked Life Data

6734735

Source:http://linkedlifedata.com/resource/pubmed/id/6734735

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1984-8-1
pubmed:abstractText
The growth rate of normal cultured Swiss 3T3 fibroblasts is function of serum concentration and the fraction of G1 cells, and hence the average residence time in G1, increases with the generation time. Serum contains two sets of factors: competence factors, essentially platelet-derived growth factor (PDGF), which induces competence in quiescent fibroblasts and prevents replicating cells from entering G0, and plasma, which allows progression. The increase in the duplication time and the duration of G1 at low serum concentration could hence be due to the fact that competence factors become limiting. The fraction of non-competent cells, operationally defined as those G1 cells unable to leave G1 in the presence of plasma alone, was determined in populations exponentially growing at serum concentrations between 5 and 20%. To do so exponentially growing cultures were shifted to plasma plus colcemid: one part of the cell population progressed through the cycle and accumulated with a G2 DNA content, whereas non-competent cells remained in G1. Analysis of the DNA distributions performed 24 h after the shift showed that as serum concentration was lowered more cells were found in the non-competent state: they were less than 5% in 20% serum and almost 50% in 5% serum. The non-competent cells constitute a dynamic fraction of the population, since in the presence of serum they can leave G1 and progress in the cycle. These data indicate that one of the steps limiting exponential growth is the acquisition of competence and that this event gives rise to heterogeneity within the G1 population.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0014-4827
pubmed:author
pubmed:issnType
Print
pubmed:volume
153
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
135-44
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1984
pubmed:articleTitle
G1 phase heterogeneity in exponentially growing Swiss 3T3 mouse fibroblasts.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't