PLASMODIUM-FALCIPARUM - A REGION OF POLYMORPHISM IN THE 3' END OF THEGENE FOR THE RING-INFECTED ERYTHROCYTE SURFACE-ANTIGEN

A clone expressing the 3' end of the RESA gene of the Palo Alto isolat e of Plasmodium falciparum was isolated by screening a h expression li brary of Mung bean nuclease-digested genomic DNA fragments with antibo dies from malaria patients. The DNA sequence of the RESA gene of this isolate has seven single-base changes compared to that seen in the Pap ua New Guinean isolate FC27. Six of the seven mutations cause amino ac id substitutions. The same amino acid sequence as the Pale Alto sequen ce is found in the Ghanaian isolate NF7. To determine whether these ar e the only changes in this region of the molecule, we performed PCR an alyses on 12 blood samples from malaria patients from Indonesia, The P ale Alto form of the RESA gene was detected in 10 of the samples and t he FC27 form of the gene was detected in the other 2 samples. No other forms of the RESA gene were found, suggesting that RESA exists in two alleles for the examined region of the gene. These results indicate t hat there are two major allelic forms of RESA present in this part of Indonesia. (C) 1994 Academic Press, Inc.