TRANSCRIPTIONAL AND NUCLEOSOMAL CHARACTERIZATION OF A SUBTELOMERIC GENE-CLUSTER FLANKING A SITE OF CHROMOSOMAL REARRANGEMENTS IN PLASMODIUM-FALCIPARUM

We have recently demonstrated that Plasmodium falciparum chromosomes a re compartmentalized into different domains: conserved and polymorphic domains; transcriptionally active and silent domains. Here we have an alyzed the transition between these domains at the structural and nucl eosomal level, This study was conducted with the end of chromosome 2 t hat is associated with cytoadherence. At this end of the chromosome, t he first set of erythrocytic genes has been mapped 85 kb from the telo mere. These genes are monocistronically transcribed as revealed by nuc lear run-on analysis. Two of these genes, PfEMP3 and KAHRP, are delete d in cytoadherent negative mutants, whereas the third gene, GLARP, is expressed in all the strains investigated. The data indicate that the polymorphic domain at this end of chromosome 2 extends into the transc ribed region. Analysis of the chromatin structure revealed that both t he transcribed domain and the subtelomeric region are organized as nuc leosomes with a periodicity of 155 +/- 5 bp.