Genetic polymorphism of the thrombospondin-related apical merozoite protein (TRAMP) of Plasmodium knowlesi in Malaysia

Parasitol Res. 2023 Jan;122(1):195-200. doi: 10.1007/s00436-022-07716-z. Epub 2022 Nov 15.

Abstract

Plasmodium knowlesi is a simian malaria parasite that causes significant zoonotic infections in Southeast Asia, particularly in Malaysia. The Plasmodium thrombospondin-related apical merozoite protein (TRAMP) plays an essential role in the invasion of the parasite into its host erythrocyte. The present study investigated the genetic polymorphism and natural selection of the full length PkTRAMP from P. knowlesi clinical isolates from Malaysia. Blood samples (n = 40) were collected from P. knowlesi malaria patients from Peninsular Malaysia and Malaysian Borneo. The PkTRAMP gene was amplified using PCR, followed by cloning into a plasmid vector and sequenced. Results showed that the nucleotide diversity of PkTRAMP was low (π: 0.009). Z-test results indicated negative (purifying) selection of PkTRAMP. The alignment of the deduced amino acid sequences of PkTRAMP of Peninsular Malaysia and Malaysian Borneo revealed 38 dimorphic sites. A total of 27 haplotypes were identified from the amino acid sequence alignment. Haplotype analysis revealed that there was no clustering of PkTRAMP from Peninsular Malaysia and Malaysian Borneo.

Keywords: Genetic polymorphism; Haplotypes; Plasmodium knowlesi; Thrombospondin-related apical merozoite protein.

MeSH terms

  • Genetic Variation
  • Humans
  • Malaria* / parasitology
  • Malaysia
  • Merozoites / metabolism
  • Plasmodium knowlesi* / genetics
  • Plasmodium knowlesi* / metabolism
  • Polymorphism, Genetic
  • Protozoan Proteins / genetics
  • Protozoan Proteins / metabolism

Substances

  • Protozoan Proteins