Inter-allelic recombination in the Plasmodium vivax merozoite surface protein 1 gene among Indian and Colombian isolates

• Published in: Malaria Journal
• Main Authors: Corredor Mauricio, Echeverri Marcela, Mohmmed Asif, Ahmad Gul, Sunil Sujatha, Maestre Amanda, Blair Silvia, Chauhan Virander S, Malhotra Pawan
• Format: Article in Journal/Newspaper
• Language: English
• Published: BMC 2004
• Subjects: Arctic medicine. Tropical medicine; RC955-962; Infectious and parasitic diseases; RC109-216; Arctic; Indian
• Online Access: https://doi.org/10.1186/1475-2875-3-4; https://doaj.org/article/4f653504d45b43f8b959e89e66f18fd6

Abstract Background A major concern in malaria vaccine development is the polymorphism observed among different Plasmodium isolates in different geographical areas across the globe. The merozoite surface protein 1 (MSP-1) is a leading vaccine candidate antigen against asexual blood stages of malaria parasite. To date, little is known about the extent of sequence variation in the Plasmodium vivax MSP-1 gene ( Pvmsp-1 ) among Indian isolates. Since P. vivax accounts for >50% of malaria cases in India and in Colombia, it is essential to know the Pvmsp-1 gene variability in these two countries to sustain it as a vaccine candidate. The extent of polymorphism in Pvmsp-1 gene among Indian and Colombian isolates is described. Methods The sequence variation in the region encompassing the inter-species conserved blocks (ICBs) five and six of Pvmsp-1 gene was examined. PCR was carried out to amplify the polymorphic region of Pvmsp-1 and the PCR products from twenty (nine Indian and 11 Colombian) isolates were sequenced and aligned with Belem and Salvador-1 sequences. Results Results revealed three distinct types of sequences among these isolates, namely, Salvador-like, Belem-like and a third type sequence which was generated due to interallelic recombination between Salvador-like sequences and Belem-like sequences. Existence of the third type in majority (44%) showed that allelic recombinations play an important role in PvMSP1 diversity in natural parasite population. Micro-heterogeneity was also seen in a few of these isolates due to nucleotide substitutions, insertions as well as deletions. Conclusions Intergenic recombination in the Pvmsp-1 gene was found and suggest that this is the main cause for genetic diversity of the Pvmsp-1 gene.