A CHROMOSOME-9 DELETION IN PLASMODIUM-FALCIPARUM RESULTS IN LOSS OF CYTOADHERENCE

Many lines of Plasmodium falciparum undergo a deletion of the right en d of chromosome 9 during in vitro culture accompanied by loss of cytoa dherence and gametocytogenesis. Selection of cytoadherent cells from a mixed population co-selects for those with an undeleted chromosome 9 and the selected cells produce gametocytes The deletion also results i n loss of expression of PfEMP1, the putative cytoadherence ligand, sug gesting that PfFMP1 or a regulatory gene controlling PfEMP1 expression and gametocytogenesis may be encoded in this region. We have isolated several markers for the deleted region and are currently using a YAC- P. falciparum library to investigate this region of the genome in deta il.