Evidence map›Paper›PMID 21408186›Full record

ArticlePloS one2011

Cloning of the repertoire of individual Plasmodium falciparum var genes using transformation associated recombination (TAR).

Annette Gaida, Marion M Becker, Christoph D Schmid, Tobias Bühlmann, Edward J Louis, Hans-Peter Beck

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In one paragraph

Article in PloS one, 2011. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 8 papers.

0numbers the graph read from it
0cells of the map it votes in
8citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

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3 · Its place in the literature

Who cites it

8 citing papers in PubMed.

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4 · The record

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5 · Who and what money

Authors and funding

6 authors.

Annette GaidaDepartment for Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland.
Marion M Becker
Christoph D Schmid
Tobias Bühlmann
Edward J Louis
Hans-Peter Beck

Funding

Wellcome Trust
6 · The paper itself

Abstract

One of the major virulence factors of the malaria causing parasite is the Plasmodium falciparum encoded erythrocyte membrane protein 1 (PfEMP1). It is translocated to It the membrane of infected erythrocytes and expressed from approximately 60 var genes in a mutually exclusive manner. Switching of var genes allows the parasite to alter functional and antigenic properties of infected erythrocytes, to escape the immune defense and to establish chronic infections. We have developed an efficient method for isolating VAR genes from telomeric and other genome locations by adapting transformation-associated recombination (TAR) cloning, which can then be analyzed and sequenced. For this purpose, three plasmids each containing a homologous sequence representing the upstream regions of the group A, B, and C var genes and a sequence homologous to the conserved acidic terminal segment (ATS) of var genes were generated. Co-transfection with P. falciparum strain ITG2F6 genomic DNA in yeast cells yielded 200 TAR clones. The relative frequencies of clones from each group were not biased. Clones were screened by PCR, as well as Southern blotting, which revealed clones missed by PCR due to sequence mismatches with the primers. Selected clones were transformed into E. coli and further analyzed by RFLP and end sequencing. Physical analysis of 36 clones revealed 27 distinct types potentially representing 50% of the var gene repertoire. Three clones were selected for sequencing and assembled into single var gene containing contigs. This study demonstrates that it is possible to rapidly obtain the repertoire of var genes from P. falciparum within a single set of cloning experiments. This technique can be applied to individual isolates which will provide a detailed picture of the diversity of var genes in the field. This is a powerful tool to overcome the obstacles with cloning and assembly of multi-gene families by simultaneously cloning each member.

Indexed as

Transformation, GeneticBase SequenceBlotting, SouthernCloning, MolecularGene LibraryGenes, ProtozoanGenetic VectorsMolecular Sequence DataPlasmodium falciparumPolymerase Chain ReactionPolymorphism, Restriction Fragment LengthProtozoan ProteinsRecombination, GeneticSequence Analysis, DNAerythrocyte membrane protein 1, Plasmodium falciparumProtozoan Proteins

Identifiers

PMID21408186
PMCPMC3049791

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.