Analysis of von Willebrand factor A domain-related protein (WARP) polymorphism in temperate and tropical Plasmodium vivax field isolates.
BACKGROUND
The identification of key molecules is crucial for designing transmission-blocking vaccines (TBVs), among those ookinete micronemal proteins are candidate as a general class of malaria transmission-blocking targets. Here, the sequence analysis of an extra-cellular malaria protein expressed in ookinetes, named von Willebrand factor A domain-related protein (WARP), is reported in 91 Plasmodium vivax isolates circulating in different regions of Iran.


METHODS
Clinical isolates were collected from north temperate and southern tropical regions in Iran. Primers have been designed based on P. vivax sequence (ctg_6991) which amplified a fragment of about 1044 bp with no size variation. Direct sequencing of PCR products was used to determine polymorphism and further bioinformatics analysis in P. vivax sexual stage antigen, pvwarp.


RESULTS
Amplified pvwarp gene showed 886 bp in size, with no intron. BLAST analysis showed a similarity of 98-100% to P. vivax Sal-I strain; however, Iranian isolates had 2 bp mismatches in 247 and 531 positions that were non-synonymous substitution [T (ACT) to A (GCT) and R (AGA) to S (AGT)] in comparison with the Sal-I sequence.


CONCLUSIONS
This study presents the first large-scale survey on pvwarp polymorphism in the world, which provides baseline data for developing WARP-based TBV against both temperate and tropical P. vivax isolates.
Gholizadeh
Saber
S
Biotechnology Research Center (BRC), Pasteur Institute of Iran (PII), Tehran, Iran. sabergholizadeh@yahoo.com
Djadid
Navid Dinparast
ND
Basseri
Hamid Reza
HR
Zakeri
Sedigheh
S
Ladoni
Hossein
H
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002980:Climate; D017931:DNA Primers / Q000235:genetics*; D006801:Humans; D007492:Iran; D016780:Malaria, Vivax / Q000517:prevention & control / Q000635:transmission; D008969:Molecular Sequence Data; D010802:Phylogeny; D010966:Plasmodium vivax / Q000235:genetics* / Q000302:isolation & purification; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D015800:Protozoan Proteins / Q000235:genetics*
D017931:DNA Primers; D015800:Protozoan Proteins; C434321:WARP protein, Plasmodium