PLASMODIUM-FALCIPARUM GENETIC DIVERSITY CAN BE CHARACTERIZED USING THE POLYMORPHIC MEROZOITE SURFACE-ANTIGEN-2 (MSA-2) GENE AS A SINGLE-LOCUS MARKER

The genetic diversity of Solomon Island Plasmodium falciparum isolates was examined using MSA-2 as a single locus marker. Amplification of M SA-2 gene fragments showed size polymorphism and the presence of mixed infections. Sequence analysis indicated a global representation of MS A-2 alleles with representatives of 3D7/CAMP allelic subfamilies and t he FCQ-27 allelic family being identified. A simplified method of char acterisation, utilising PCR-RFLPs of MSA-2 gene fragments, was develop ed. The RFLPs allowed identification of allelic families and further d istinction within the 3D7/CAMP family. The amplification of MSA-2 gene fragments from culture derived lines revealed a loss of diversity for a number of Solomon Island isolates. Genomic diversity was confirmed for Solomon Island lines, along with Papua New Guinean and Thai lines, by the generation of 7H8/6 fingerprints. All lines were distinct and band sharing frequencies and Wagner tree construction failed to identi fy any geographic clustering.