Switch to
Predicate | Object |
---|---|
rdf:type | |
lifeskim:mentions | |
pubmed:issue |
Pt 2
|
pubmed:dateCreated |
1982-5-21
|
pubmed:abstractText |
To study the effect of gene dosage on gene expression, lambda plac5cI857O29P3, a replication defective lambda phage carrying part of the lac operon (containing the lac promotor, operator and z gene) in the b2 region was studied in Escherichia coli strain JC6256 where the lac operon is deleted and at a temperature where the lambda repressor is inactive. In measuring the synthesis of beta-galactosidase, it was possible to separate the effects of the lac promoter from those of the phage promoter. When the synthesis of beta-galactosidase was initiated from the inserted lac promoter in JC6256(lambda +) in the presence of additional cyclic AMP, the rate and level of beta-galactosidase synthesis were directly proportional to the multiplicity of infection (gene dosage). Furthermore, beta-galactosidase synthesis was initiated about 5 min after infection, just as with isopropyl-beta-D-thiogalactoside (IPTG) induction. When the synthesis of beta-galactosidase was initiated from the phage promoter in JC6256 in the absence of additional cyclic AMP, the rate and level of beta-galactosidase synthesis were again linearly proportional to gene dosage. On the other hand, initiation of beta-galactosidase synthesis was delayed until 10 to 20 min after infection. These results suggest that: (i) in the absence of negative controlling factors, the extent of gene expression is proportional to gene dosage; (ii) varying the gene dosage can be used to regulate gene expression.
|
pubmed:language |
eng
|
pubmed:journal | |
pubmed:citationSubset |
IM
|
pubmed:chemical | |
pubmed:status |
MEDLINE
|
pubmed:month |
Feb
|
pubmed:issn |
0022-1317
|
pubmed:author | |
pubmed:issnType |
Print
|
pubmed:volume |
58
|
pubmed:owner |
NLM
|
pubmed:authorsComplete |
Y
|
pubmed:pagination |
297-304
|
pubmed:dateRevised |
2000-12-18
|
pubmed:meshHeading |
pubmed-meshheading:6278060-Bacteriophage lambda,
pubmed-meshheading:6278060-Cyclic AMP,
pubmed-meshheading:6278060-Escherichia coli,
pubmed-meshheading:6278060-Gene Expression Regulation,
pubmed-meshheading:6278060-Genes, Regulator,
pubmed-meshheading:6278060-Genes, Viral,
pubmed-meshheading:6278060-Lac Operon,
pubmed-meshheading:6278060-beta-Galactosidase
|
pubmed:year |
1982
|
pubmed:articleTitle |
Gene dosage as a regulatory factor for gene expression. I. In lambda plac5-infected cells.
|
pubmed:publicationType |
Journal Article
|