Homopolymer tract organization in the human malarial parasite Plasmodium falciparum and related Apicomplexan parasites - INRAE - Institut national de recherche pour l’agriculture, l’alimentation et l’environnement Accéder directement au contenu
Article Dans Une Revue BMC Genomics Année : 2014

Homopolymer tract organization in the human malarial parasite Plasmodium falciparum and related Apicomplexan parasites

Résumé

Background Homopolymeric tracts, particularly poly dA.dT, are enriched within the intergenic sequences of eukaryotic genomes where they appear to act as intrinsic regulators of nucleosome positioning. A previous study of the incomplete genome of the human malarial parasite Plasmodium falciparum reports a higher than expected enrichment of poly dA.dT tracts, far above that anticipated even in this highly AT rich genome. Here we report an analysis of the relative frequency, length and spatial arrangement of homopolymer tracts for the complete P. falciparum genome, extending this analysis to twelve additional genomes of Apicomplexan parasites important to human and animal health. In addition, using nucleosome-positioning data available for P. falciparum, we explore the correlation of poly dA.dT tracts with nucleosome-positioning data over key expression landmarks within intergenic regions. Results We describe three apparent lineage-specific patterns of homopolymeric tract organization within the intergenic regions of these Apicomplexan parasites. Moreover, a striking pattern of enrichment of overly long poly dA.dT tracts in the intergenic regions of Plasmodium spp. uniquely extends into protein coding sequences. There is a conserved spatial arrangement of poly dA.dT immediately flanking open reading frames and over predicted core promoter sites. These key landmarks are all relatively depleted in nucleosomes in P. falciparum, as would be expected for poly dA.dT acting as nucleosome exclusion sequences. Conclusions Previous comparative studies of homopolymer tract organization emphasize evolutionary diversity; this is the first report of such an analysis within a single phylum. Our data provide insights into the evolution of homopolymeric tracts and the selective pressures at play in their maintenance and expansion.
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Dates et versions

hal-02633699 , version 1 (27-05-2020)

Identifiants

Citer

Karen Russell, Chia-Ho Cheng, Jeffrey W. Bizzaro, Nadia Ponts, Richard D. Emes, et al.. Homopolymer tract organization in the human malarial parasite Plasmodium falciparum and related Apicomplexan parasites. BMC Genomics, 2014, 15, 17 p. ⟨10.1186/1471-2164-15-848⟩. ⟨hal-02633699⟩

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