Project description:Artemisinin resistance in Plasmodium falciparum malaria has emerged in western Cambodia. This is a major threat to global plans to control and eliminate malaria as the artemisinins are a key component of antimalarial treatment throughout the world. Using DNA microarrays we identify key features of a transcriptional profile that are associated with the delayed parasite clearance phenotype. These include reduced expression of several basic metabolic and cellular pathways in the early stages, and increased expression of essentially all functionalities associated with protein metabolism in the later stages of P. falciparum intraerythrocytic development. This is consistent with the reduced ring stage susceptibility that characterizes artemisinin resistant P. falciparum. This modulation of the P. falciparum intraerythrocytic transcriptome may result from differential expression of several regulatory proteins such as transcription factors of chromatin remodeling associated factors. In addition, the artemisinin resistant phenotype is strongly associated with a specific pattern of copy number variations, some of which are linked with differential expression of several regulatory proteins such as histone 4 and zinc permease. This study reports the first global transcriptional survey of artemisinin resistant parasites and provides a set of candidate genes for further investigation. 6 P. falciparum parasites (field isolates) which are either Artemsinin resistant or sensitive from 3 study sites (Pailin in Cambodia, Xepon in Laos, Mae Sot in Thailand) were sampled and harvested for genomic DNA. gDNA from a total of 6 samples were extracted by phenol chloroform. Synthesis of labelled target DNA was carried out as previously described: Mackinnon, M.J. et al. Comparative transcriptional and genomic analysis of Plasmodium falciparum field isolates. PLoS Pathog 5, e1000644 (2009), and used in comparative genomic microarray hybridizations (CGH).
Project description:A custom resequencing array for analysis of field isolates of plasmdium falciparum was created. Test of DNA with genotypes known at all loci genotyped by the microarray as well as test of accuracy correlation with amounts of DNA added to each array
Project description:Artemisinin resistance in Plasmodium falciparum malaria has emerged in western Cambodia. This is a major threat to global plans to control and eliminate malaria as the artemisinins are a key component of antimalarial treatment throughout the world. Using DNA microarrays we identify key features of a transcriptional profile that are associated with the delayed parasite clearance phenotype. These include reduced expression of several basic metabolic and cellular pathways in the early stages, and increased expression of essentially all functionalities associated with protein metabolism in the later stages of P. falciparum intraerythrocytic development. This is consistent with the reduced ring stage susceptibility that characterizes artemisinin resistant P. falciparum. This modulation of the P. falciparum intraerythrocytic transcriptome may result from differential expression of several regulatory proteins such as transcription factors of chromatin remodeling associated factors. In addition, the artemisinin resistant phenotype is strongly associated with a specific pattern of copy number variations, some of which are linked with differential expression of several regulatory proteins such as histone 4 and zinc permease. This study reports the first global transcriptional survey of artemisinin resistant parasites and provides a set of candidate genes for further investigation. 11 P. falciparum parasites (field isolates) which are either Artemsinin resistant or sensitive from 3 study sites (Pailin in Cambodia, Xepon in Laos, Mae Sot in Thailand) were sampled, grown ex-vivo over 48 hours and harvested at regular intervals. RNA from a total of 91 samples were extracted. Synthesis of target DNA was carried out as previously described: Mackinnon, M.J. et al. Comparative transcriptional and genomic analysis of Plasmodium falciparum field isolates. PLoS Pathog 5, e1000644 (2009), and used in microarray hybridizations.
Project description:A custom resequencing array for analysis of field isolates of plasmdium falciparum was created. Test of DNA with genotypes known at all loci genotyped by the microarray as well as test of accuracy correlation with amounts of DNA added to each array Comparison of test DNA from lab and clinical isolates between genotyped generated by next-generation sequencing and this new custom DNA microarray.
Project description:Determination of gene expression level changes of whole genome during Plasmodium falciparum development in early liver stage (at 24h and 48h), compared to mixed blood stage and sporozoite stage. A set of Genes selected from this expression analysis are further verified by qPCR and a sub-set were tested for their vaccine efficacy. 6 genomic tiling arrays: 3 time points in early liver infection (spz, hr24, hr48), and 3 blood stage isolates