Plasmodium falciparum
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA302635 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:The aim of this study was to describe gene copy number variation in Plasmodium falciparum parasites sourced from high vs. low malaria transmission settings in east Africa in order to test the hypothesis that malaria parasites are locally adapted to their environment. In three separate experiments, parasites from ‘High’ vs. ‘Low’ transmission populations were taken from non-immune children and evaluated for copy number variants by microarray against a reference genome. Two of these population comparisons were geographic in nature while the third was temporal, i.e., before and after a marked decline in malaria. This study is described in Simam et al. 2018 BMC Genomics.
2018-05-30 | GSE113087 | GEO
Project description:Piperaquine Resistance is Associated with a Copy Number Variation on Chromosome 5 in Drug-Pressured Plasmodium falciparum Parasites
| PRJNA138221 | ENA
Project description:Here we fully characterize the genomes of 14 Plasmodium falciparum patient isolates taken recently from the Iquitos regions using genome-scanning, a microarray-based technique which delineates the majority of single-base changes, indels and copy number variants distinguishing the coding regions of two clones. We show that the parasite population in the Peruvian Amazon is highly structured with a limited number of genotypes and low recombination frequencies. Despite the essentially clonal nature of some isolates, we see high frequencies of mutations in subtelomeric highly variable genes and internal var genes indicating mutations arising during self-mating or mitotic replication. The data also reveal that 1 or 2 meioses separate different isolates showing that P. falciparum clones isolated from different individuals in defined geographical regions could be useful in linkage analyses or quantitative trait locus studies. Through pair-wise comparisons of different isolates we discovered point mutations in the apicoplast genome that are close to known mutations that confer clindamycin resistance in other species but which were hitherto unknown in malaria parasites. Subsequent drug sensitivity testing revealed over 100-fold increase clindamycin EC50 in strains harboring one of these mutations. This evidence of clindamycin resistant parasites in the Amazon suggests a shift should be made in health policy away from quinine+clindamycin therapy for malaria in pregnant women and infants and that the development of new lincosamide antibiotics for malaria should be reconsidered. Genome DNA from Peruvian Isolates vs. Reference 3D7
2010-08-04 | E-GEOD-22861 | biostudies-arrayexpress
Project description:Here we fully characterize the genomes of 14 Plasmodium falciparum patient isolates taken recently from the Iquitos regions using genome-scanning, a microarray-based technique which delineates the majority of single-base changes, indels and copy number variants distinguishing the coding regions of two clones. We show that the parasite population in the Peruvian Amazon is highly structured with a limited number of genotypes and low recombination frequencies. Despite the essentially clonal nature of some isolates, we see high frequencies of mutations in subtelomeric highly variable genes and internal var genes indicating mutations arising during self-mating or mitotic replication. The data also reveal that 1 or 2 meioses separate different isolates showing that P. falciparum clones isolated from different individuals in defined geographical regions could be useful in linkage analyses or quantitative trait locus studies. Through pair-wise comparisons of different isolates we discovered point mutations in the apicoplast genome that are close to known mutations that confer clindamycin resistance in other species but which were hitherto unknown in malaria parasites. Subsequent drug sensitivity testing revealed over 100-fold increase clindamycin EC50 in strains harboring one of these mutations. This evidence of clindamycin resistant parasites in the Amazon suggests a shift should be made in health policy away from quinine+clindamycin therapy for malaria in pregnant women and infants and that the development of new lincosamide antibiotics for malaria should be reconsidered.
2010-08-05 | GSE22861 | GEO
Project description:The determinants of transcriptional regulation in malaria parasites remain elusive. The presence of a well-characterized gene expression cascade shared by different Plasmodium falciparum strains could imply that transcriptional regulation and its natural variation do not contribute significantly to the evolution of parasite drug resistance. To clarify the role of transcriptional variation as a source of stain-specific diversity in the most deadly malaria species and to find genetic loci that dictate variations in gene expression, we examined genome-wide expression level polymorphisms (ELPs) in a genetic cross between phenotypically distinct parasite clones. Significant variation in gene expression is observed through direct co-hybridizations of RNA from different P. falciparum clones. Nearly 18% of genes were regulated by a significant eQTL. The genetic determinants of most of these ELPs resided in hotspots that are physically distant from their targets. The most prominent regulatory locus, influencing 269 transcripts, coincided with a Chromosome 5 amplification event carrying the drug resistance gene, pfmdr1, and 13 other genes. Drug selection pressure in the Dd2 parental clone lineage led not only to a copy number change in the pfmdr1 gene but also to increased copies of putative neighboring regulatory factors that, in turn, broadly influence the transcriptional network. Previously unrecognized transcriptional variation, controlled by polymorphic regulatory genes and possibly master regulators within large copy number variants, contributes to sweeping phenotypic evolution in drug-resistant malaria parasites. Keywords: Segregation patterns of gene expression levels.
2008-11-20 | GSE12515 | GEO
Project description:The determinants of transcriptional regulation in malaria parasites remain elusive. The presence of a well-characterized gene expression cascade shared by different Plasmodium falciparum strains could imply that transcriptional regulation and its natural variation do not contribute significantly to the evolution of parasite drug resistance. To clarify the role of transcriptional variation as a source of stain-specific diversity in the most deadly malaria species and to find genetic loci that dictate variations in gene expression, we examined genome-wide expression level polymorphisms (ELPs) in a genetic cross between phenotypically distinct parasite clones. Significant variation in gene expression is observed through direct co-hybridizations of RNA from different P. falciparum clones. Nearly 18% of genes were regulated by a significant eQTL. The genetic determinants of most of these ELPs resided in hotspots that are physically distant from their targets. The most prominent regulatory locus, influencing 269 transcripts, coincided with a Chromosome 5 amplification event carrying the drug resistance gene, pfmdr1, and 13 other genes. Drug selection pressure in the Dd2 parental clone lineage led not only to a copy number change in the pfmdr1 gene but also to increased copies of putative neighboring regulatory factors that, in turn, broadly influence the transcriptional network. Previously unrecognized transcriptional variation, controlled by polymorphic regulatory genes and possibly master regulators within large copy number variants, contributes to sweeping phenotypic evolution in drug-resistant malaria parasites. Keywords: Segregation patterns of gene expression levels. A total of 36 test parasite samples (Dd2, HB3, and progeny) from a single time point in the parasite life cycle (18 hours post RBC invasion) were co-hybridized to a common reference HB3 sample, each a single replicate.
2010-05-16 | E-GEOD-12515 | biostudies-arrayexpress
Project description:Continual challenge of 107 ARMD Dd2 parasites with 0.3µM DSM1, a novel dihydroorotate dehydrogenase (DHODH) inhibitor, reproducibly generated ~5-fold resistance and 3-fold amplification of 30-100Kb DNA, always including the DHODH gene. Subsequent 3-10µM DSM-1 pressure selected for ~10-fold amplification of the copy number variant (CNV), and over 100-fold resistance. Target-specific and genome-wide DNA sequencing revealed no additional mutations contributing to DSM1 resistance.
2013-05-01 | GSE37306 | GEO
Project description:Nanopore sequencing of drug-resistance-associated genes in malaria parasites, Plasmodium falciparum
| PRJDB5281 | ENA
Project description:Genome wide transcriptome analyses could reveal whether parasites causing severe malarial disease express different genes to those causing uncomplicated malaria. This knowledge could inform therapy and vaccine design targeting severe disease. Venous samples were collected from patients with severe (n=23) and uncomplicated (n=21) malaria attending a healthcare facility in Timika, Papua Province, Indonesia. This area has unstable malaria transmission with estimated annual parasite incidence of 450 per 1000 population and symptomatic illness in all ages. Severe malaria was defined as peripheral parasitaemia with at least one modified World Health Organization (WHO) criterion of severity. Erythrocytes were immediately isolated from whole blood, solubilised in RNA preservative and frozen. Libraries were 100 bp paired end sequenced on a 2500-HT Hiseq (Illumina) using RapidRun chemistry (Illumina).
2018-02-08 | E-MTAB-5860 | biostudies-arrayexpress
Project description:Plasmodium falciparum secretes extracellular vesicles that contain RNA. The biological benefit of this secretion to the secreting parasite is not known. Here, we sequenced the RNA content of extracellular vesicles and compared with that of the secreting whole parasites. The data suggests that extracellular vesicles might be part of a post-transcriptional regulatory mechanism that shapes intracellular RNA levels in the parasite.
2023-08-23 | GSE241277 | GEO