title: Polymorphic patterns of the merozoite surface protein-3β in Korean isolates of Plasmodium vivax.
abstract: BACKGROUND
  The merozoite surface protein-3β of Plasmodium vivax (PvMSP-3β) is one of the candidate antigens for blood stage malaria vaccine development. The polymorphisms in PvMSP-3β have been reported in certain P. vivax isolates. However, the diversity of PvMSP-3β throughout its global distribution has not been well understood. In this study, the genetic diversity and the effects of natural selection in PvMSP-3β among P. vivax Korean isolates were analysed.
  
  
  METHODS
  Blood samples were collected from 95 patients with vivax malaria in Korea. The region flanking full-length PvMSP-3β was amplified by polymerase chain reaction and cloned into a TA cloning vector. The PvMSP-3β sequence of each isolate was determined and the polymorphic characteristics and effects of natural selection were analysed using the DNASTAR, MEGA4, and DnaSP programs.
  
  
  RESULTS
  Five different subtypes of PvMSP-3β were identified based on single nucleotide polymorphisms (SNPs), insertions, and deletions. Although a high level of sequence diversity was observed in the PvMSP-3β gene, the coiled-coil tertiary structure of the PvMSP-3β protein was well conserved in all of the sequences. The PvMSP-3β of Korean isolates is under natural selection. DNA polymerase slippage and intragenic recombination likely contributed to PvMSP-3β diversity in Korean P. vivax isolates.
  
  
  CONCLUSIONS
  The PvMSP-3β of Korean P. vivax isolates displayed polymorphisms, with SNPs, insertions and deletions scattered throughout of the gene. These results of parasite heterogeneity are relevant to the development of a PvMSP-3β based vaccine against P. vivax and the implementation of malaria control programmes in Korea.
authors.forename: Jung-Mi
authors.initials: JM
authors.lastname: Kang
authors.forename: Hye-Lim
authors.initials: HL
authors.lastname: Ju
authors.forename: Pyo Yun
authors.initials: PY
authors.lastname: Cho
authors.forename: Sung-Ung
authors.initials: SU
authors.lastname: Moon
authors.forename: Seong Kyu
authors.initials: SK
authors.lastname: Ahn
authors.forename: Woon-Mok
authors.initials: WM
authors.lastname: Sohn
authors.forename: Hyeong-Woo
authors.initials: HW
authors.lastname: Lee
authors.affiliation: Department of Parasitology and Tropical Medicine, and Institute of Health Sciences, Gyeongsang National University School of Medicine, Jinju 660-751, Republic of Korea. tongsookim@inha.ac.kr.
authors.forename: Tong-Soo
authors.initials: TS
authors.lastname: Kim
authors.forename: Byoung-Kuk
authors.initials: BK
authors.lastname: Na
mesh_terms: D000595:Amino Acid Sequence; D000953:Antigens, Protozoan / Q000737:chemistry / Q000235:genetics*; D003001:Cloning, Molecular; D016000:Cluster Analysis; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D019143:Evolution, Molecular; D005822:Genetic Vectors; D006801:Humans; D016780:Malaria, Vivax / Q000469:parasitology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D010966:Plasmodium vivax / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D011487:Protein Conformation; D015800:Protozoan Proteins / Q000737:chemistry / Q000235:genetics*; D056910:Republic of Korea; D012641:Selection, Genetic; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
chemical_list: D000953:Antigens, Protozoan; D016054:DNA, Protozoan; D015800:Protozoan Proteins; C089133:merozoite surface protein 3, Plasmodium