Please note that we have stopped the regular imports of Gene Expression Omnibus (GEO) data into ArrayExpress. This may not be the latest version of this experiment.
E-GEOD-54253 - A new Agilent 15K cross strain P. falciparum microarray optimized for the transcriptome analysis of Indian P. falciparum isolates
Released on 17 January 2016, last updated on 24 January 2016
Genomic variation is an inherent phenomena observed among members of same species belonging to different geographical locations. In case of P. falciparum, an apicomplexan protozoan parasite, its 22.8 MB nuclear genome is known to display vast genetic diversity in the subtelomeric compartments having but not exclusively variant gene families like var, rifins and stevors and examples in other elements of the genome have recently been documented. Microarrays, relies solely on the genomic sequence information to capture the relevant transcript abundance and needs to consider these variations into account for revealing true transcriptional variation.Here, we describe the designing strategy of a custom P. falciparum 15K array using Agilent platform to study the transcriptome of Indian field isolates for which genome sequence information is limited. Array contains probes representing genome sequence of two distinct geographical isolates (i.e 3D7 and HB3) and subtelomeric var gene sequence of a third isolate (IT4) known to adhere in culture condition. Probes in the array have been selected based on their efficiency to detect transcripts by performing a 244K array experiment representing multiple probes per gene/transcript. Array performance was evaluated and validated using RNA materials from P. falciparum clinical isolates obtained directly from patients with differing clinical conditions due to malaria infection.Due to pre probe screening large percentage (91 %) of the represented transcripts could be detected from Indian P. falciparum isolates. Replicated probes and multiple probes representing the same gene showed perfect correlation between them suggesting good probe performance. Additional transcripts could be detected due to inclusion of unique probes representing HB3 strain transcripts. Variant surface antigen (VSA) transcripts were detected by optimized probes representing the VSA genes of three geographically distinct strains. Plasmodium falciparum isolates were collected from patients (n=13) with differing clinical conditions. The patients exhibited symptoms categorized as uncomplicated (n=6) or complicated malaria (n=7). Criteria for determination of complicated disease were based on World Health Organization year 2000 guidelines. Microarray array based transcriptional profiling was carried out to evaluate the performance of the array.
transcription profiling by array
Ashis Kumar Das <email@example.com>, Amit K Subudhi, Ashis Das, Dhanpat Kochar, P A Boopathi, Sanjay Kochar