Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1994-6-30
pubmed:abstractText
Study of the molecular basis for Legionella pneumophila pathogenicity would be facilitated with an efficient mutagen that can not only mark genomic mutations, but can also be used to reflect gene expression during macrophage infection. A derivative of Tn903, Tn903dlllacZ, is shown to transpose with high efficiency in L. pneumophila. Tn903dlllacZ encodes resistance to kanamycin (KmR) and carries a 5' truncated 'lacZ gene that can form translational fusions to L. pneumophila genes upon transposition. The cis-acting Tn903 transposase is supplied outside Tn903dlllacZ, and hence chromosomally integrated copies are stable. KmR LacZ+ insertion mutants of L. pneumophila were isolated and shown by DNA hybridization to carry a single Tn903dlllacZ inserted within their chromosomes at various locations. One particular KmR LacZ+ mutant, AB1156, does not produce the brown pigment (Pig-) characteristic of Legionella species. Tn903dlllacZ is responsible for this phenotype since reintroduction of the transposon-linked mutation into a wild-type background results in a Pig- phenotype. L. pneumophila pigment production is normally observed in stationary-phase growth of cells in culture, and beta-galactosidase activity measured from the pig::lacZ fusion increased during the logarithmic-phase growth and peaked at the onset of stationary phase. Interestingly, pig::lacZ expression also increased during macrophage infection. The pigment itself, however, does not appear to be required for L. pneumophila to grow within or kill host macrophages.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0950-382X
pubmed:author
pubmed:issnType
Print
pubmed:volume
11
pubmed:geneSymbol
pig
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
641-53
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Mutagenesis of Legionella pneumophila using Tn903 dlllacZ: identification of a growth-phase-regulated pigmentation gene.
pubmed:affiliation
Department of Microbiology, College of Physicians and Surgeons, Columbia University, New York, New York 10032.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't