Sequence diversity and molecular evolution of the merozoite surface antigen 2 of plasmodium falciparum
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Eleven new alleles of the Plasmodium falciparum merozoite surface antigen 2 (MSA2) from Papua New Guinea were analyzed by direct sequencing of polymerase chain reaction (PCR) products. We have used the sequence information to trace the molecular evolution of MSA2. The repeats of ten alleles belonging to the 3D7 allelic family differed considerably in size, nucleotide sequence, and repeat copy number. In the repeat region of these new alleles, codon usage was extremely biased with an exclusive use of NNT codons. Another new allele sequenced belonged to the FC27 family and confirmed the family-specific conserved structure of 96 and 36 bp repeats. In order to assess sequence microheterogeneity within samples defined as the same genotype by restriction fragment length polymorphism (RFLP), we have analyzed single-strand conformation polymorphism (SSCP) of different samples of the most frequent allele (D10 of the FC27 family) in the study population. No sequence heterogeneity could be detected within the repeat region. Based on analysis of the repeat regions in both allelic families, we discuss the hypothesis of a different evolutionary strategy being represented by each of the allelic families.
Kew wordsMerozoite surface antigen 2 Nucleotide sequence comparisons Molecular evolution
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- Alpers MP, AI-Yaman F, Beck H-P, Bhatia KK, Hii J, Lewis DJ, Paru R, Smith T (1992) The Malaria Vaccine Epidemiology and Evaluation Project of Papua New Guinea: rationale and baseline studies. PNG Med J 35:285–297Google Scholar
- Frontali C, Pizzi E (1991) Conservation and divergence of repeated structures in Plasmodium genomes: the molecular drift. Acta Leid 60(l):69–81Google Scholar
- Good MF, Pombo D, Quakyi IA, Riley EM, Houghten RA, Menon A, Ailing DW, Berzofsky JA, Miller LH (1988) Human T-cell recognition of the circumsporozoite protein of Plasmodium falciparum:immunodominant T-cell domains map to the polymorphic regions of the molecule. Proc Natl Acad Sci USA 85:1199–1203PubMedCrossRefGoogle Scholar
- Huang X (1994) On global sequence alignment. Computer Applications Biosci 10(3):227–235Google Scholar