Unknown,Transcriptomics,Genomics,Proteomics

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Plasmodium knowlesi gene expression differs in ex vivo compared to in vitro blood-stage cultures

ABSTRACT: The purpose of this reasearch is to identify and evaluate the global gene expression of Plasmodium knowlesi blood-stage parasites and specifically compare the gene expression profiles of samples derived from ex vivo versus long-term in vitro cultures. For ex vivo samples, a rhesus monkey was infected with P. knowlesi to obtain ring iRBCs to establish a short-term culture to immediately collect ex vivo derived time points every 4 hours in the course of the parasite’s 24-hour life cycle. For in vivo samples, they were generated from the same clone in the ex vivo culture adapted to long-term in vitro culture and were collected every 4 hours in the course of the parasite's 24-hour life cycle. Two replicate experiments(Aa and Ha) were developed from in vitro cultures. Samples labeled with Cy5 were hybridized against a reference RNA pool labeled with Cy3, consisting of equal amounts of P. knowlesi RNA from each time point.

ORGANISM(S): Plasmodium knowlesi

SUBMITTER: Zbynek Bozdech

PROVIDER: E-GEOD-62886 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

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Project description:Drug resistance in Plasmodium falciparum remains a challenge for the malaria eradication programs around the world. With the emergence of artemisinin resistance, the efficacy of the partner drugs in the artemisinin combination therapies (ACT) that include quinoline based drugs is becoming critical. So far only few resistance markers have been identified and verified from which only two ABC transmembrane transporters namely PfMDR1 and PfCRT have been experimentally verified. Another P. falciparum ABC transporter, the multidrug resistance-associated protein (PfMRP2) represents an additional possible factor of drug resistance in P. falciparum. In this study, we identify a parasite clone that is derived from the 3D7 P. falciparum strain and which shows increased resistance to chloroquine and mefloquine through the trophozoite and schizont stages. We demonstrate that the resistance phenotype is caused by a 4.1 kb deletion in the 5M-bM-^@M-^Y upstream region of the pfmrp2 gene that leads to an alteration in the pfmrp2 transcription that result in increased levels of PfMRP2 protein. These results also suggest the importance of putative promoter elements in regulation of gene expression during the P. falciparum intra-erythrocytic developmental cycle and the potential of such genetic polymorphisms to underlie drug resistance phenotypes. Presented here are the data from microarray-based genome-wide transcriptomic and genomic studies of the drug-sensitive and drug-resistant 3D7 clones 11C/wt and 6A/mut. 2 P. falciparum lab clones derived from 3D7 strain were harvested during the intra-erythrocytic cycle at 8hr intervals over 48 hours to obtain a total of 6 time point samples per clone. RNA from a total of 12 samples were extracted. Synthesis of target DNA was carried out as described in Bozdech, Z., S. Mok & A. P. Gupta, (2013) DNA microarray-based genome-wide analyses of Plasmodium parasites. Methods in molecular biology 923: 189-211 and used in replicate microarray hybridizations against a common RNA reference pool of 3D7 strain.

Project description:Drug resistance in Plasmodium falciparum remains a challenge for the malaria eradication programs around the world. With the emergence of artemisinin resistance, the efficacy of the partner drugs in the artemisinin combination therapies (ACT) that include quinoline based drugs is becoming critical. So far only few resistance markers have been identified and verified from which only two ABC transmembrane transporters namely PfMDR1 and PfCRT have been experimentally verified. Another P. falciparum ABC transporter, the multidrug resistance-associated protein (PfMRP2) represents an additional possible factor of drug resistance in P. falciparum. In this study, we identify a parasite clone that is derived from the 3D7 P. falciparum strain and which shows increased resistance to chloroquine and mefloquine through the trophozoite and schizont stages. We demonstrate that the resistance phenotype is caused by a 4.1 kb deletion in the 5M-bM-^@M-^Y upstream region of the pfmrp2 gene that leads to an alteration in the pfmrp2 transcription that result in increased levels of PfMRP2 protein. These results also suggest the importance of putative promoter elements in regulation of gene expression during the P. falciparum intra-erythrocytic developmental cycle and the potential of such genetic polymorphisms to underlie drug resistance phenotypes. Presented here are the data from microarray-based genome-wide transcriptomic and genomic studies of the drug-sensitive and drug-resistant 3D7 clones 11C/wt and 6A/mut. 2 P. falciparum lab clones derived from 3D7 strain were harvested during the intra-erythrocytic cycle for genomic DNA. gDNA were extracted by phenol chloroform. Synthesis of labelled target DNA was carried out as previously described: Bozdech, Z., M. Llinas, B. L. Pulliam, E. D. Wong, J. Zhu & J. L. DeRisi, (2003) The transcriptome of the intraerythrocytic developmental cycle of Plasmodium falciparum. PLoS Biol 1: E5, and used in comparative genomic microarray hybridizations (CGH).

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Plasmodium knowlesi gene expression differs in ex vivo compared to in vitro blood-stage cultures

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