Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
1991-10-31
pubmed:databankReference
pubmed:abstractText
The multidrug resistance (MDR) phenotype in mammalian tumor cells can involve amplification of mdr genes that results in overexpression of the protein product termed P-glycoprotein. Chloroquine resistance (CQR) in Plasmodium falciparum has similarities with the MDR phenotype in tumor cells, and some isolates of P. falciparum have amplified levels of the pfmdr1 gene. To investigate the nature and origin of pfmdr1 amplicons, we have cloned large regions of a 110-kb amplicon from the CQR cloned isolate B8 by using the yeast artificial chromosome system. We have identified and sequenced the breakpoints of the amplicon by a novel method employing inverted polymerase chain reaction that is applicable to analysis of any large-scale repeat. We show that the five copies of the amplicon in this isolate are in a head to tail configuration. A string of 30 A's flank the breakpoints on each side of the amplified segment, suggesting a mechanism for the origin of the tandem amplification. Polymerase chain reaction analysis with oligonucleotides that cross the B8 breakpoint has shown in 26 independent CQR isolates, 16 of which contain amplified copies of pfmdr1, that amplification of the pfmdr1 gene in P. falciparum has arisen as multiple independent events. These results suggest that this region of the genome is under strong selective pressure.
pubmed:commentsCorrections
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pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0270-7306
pubmed:author
pubmed:issnType
Print
pubmed:volume
11
pubmed:geneSymbol
pfmdr1
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5244-50
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Amplification of the multidrug resistance gene pfmdr1 in Plasmodium falciparum has arisen as multiple independent events.
pubmed:affiliation
Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't