Genetic diversity and natural selection of three blood-stage 6-Cys proteins in Plasmodium vivax populations from the China-Myanmar endemic border

PvGAMA reticulocyte binding activity: predicting conserved functional regions by natural selection analysis

“…Therefore, the immune response must be directed against conserved regions to avoid different parasite strains evading immunity, thereby reducing vaccine efficacy. According to the selection signal identification strategy, low genetic diversity was found in the GAMA-encoding gene, comparable to that observed in msp4 [55, 56], msp7A/7 K/7 F/7 L [57, 58], msp8 [59], msp10 [57, 59], pv12 , pv38 [22, 24], pv41 [23, 24], rap1/2 [60] and ron4 [48] which seem involved in host cell invasion. Despite the lack of statistically significant values for d N -d S difference, K S divergence amongst species was greater than K N , suggesting negative selection.…”

“…Cornejo et al [20] and Garzón-Ospina et al [19] identified natural selection signals in P. vivax genes when analysing the sequences of five genomes from different locations [21]. These results were supported by earlier studies, increasing the number of sequences analysed [22–24]. This type of analysis could therefore provide a viable approach for selecting conserved antigens that are subject to functional restrictions.…”

The s48/45 six-cysteine proteins: mediators of interaction throughout the Plasmodium life cycle

“…The interaction of Pv12 and Pv41 has recently been reported in addition to a novel interaction with PVX_110945 (Hostetler et al, 2015). Low genetic diversity was observed for Pv12 in a Colombian parasite population (Forero-Rodriguez et al, 2014) but a higher number of polymorphisms was found in parasite populations from the China-Myanmar border (Wang et al, 2014). Pv12 is recognized by sera of naturally infected patients (Chen et al, 2010; Moreno-Perez et al, 2013; Franca et al, 2016) and a strong association in reduced risk of clinical disease and antibody levels was recently reported (Franca et al, 2016).…”

“…Positive balancing selection was suggested for Pv41, particularly in the C-terminus of parasites from the China-Myanmar border (Wang et al, 2014). Alternatively, low genetic diversity was found for Pv41 in parasites from Colombia with a few substitutions in the C-terminus under positive selection (Forero-Rodriguez et al, 2014).…”

“…In P. vivax , Pv38 has two s48/45 domains, however the N-terminal domain has five cysteines rather than four (Wang et al, 2014; http://pgsh.soe.ucsc.edu/). Pv38 was reported to be present in membranes from asexual blood stages by western blot analysis and localized on schizonts with a speckled pattern (Mongui et al, 2008).…”