Anopheles stephensi

Gunarathna, Isuru, Spear, Joseph D. & Carter, Tamar E., 2024, Multi-locus investigation of AnopheLeS-mediated selective pressure on PLaSModiUM FaLCiparUM in Africa, Parasites & Vectors (530) 17 (1), pp. 1-16 : 14

Implications for An. stephensi invasion in Africa

Given that Pfs 47 in African P. falciparum populations exhibited signals of neutral evolution in relation to the current sympatric vector populations ( An. gambiae , An. funestus , etc.), we aimed to investigate how the evolution of Pfs47 might be influenced by the introduction of An. stephensi . As an initial step, we examined the P47Rec ortholog in An. stephensi . Since the P47Rec coding sequence in An. gambiae in Africa was fully conserved, we wanted to investigate the number of amino acid changes in P47Rec ortholog in invasive An. stephensi . We compared the amino acid sequence of the P47Rec ortholog in An. stephensi from Ethiopia with the An.gambiae sequence and found 18 amino acid differences. Tese findings combined with phylogenetic analysis indicating differentiation between An. stephensi and the African species ( An. gambiae bootstrap value = 100 and An. funestus bootstrap value = 100) support the potential for new P. falciparum haplotype compatibilities in Africa with the arrival, spread, and establishment of the invasive An. stephensi . In addition, the phylogenetic analysis revealed a close relationship between P47Rec in the invasive An. stephensi and the SDA500 An. stephensi strain (bootstrap = 100). Te SDA500 strain is known to be highly susceptible to both I248L haplotypes in Pfs 47 in P. falciparum [ 18]. If the Pf47Rec was the gene that underwent artificial selection leading to higher susceptibility, it is possible the same patterns of susceptibility would be observed in An. stephensi with the similar P47Rec sequence. Terefore, the presence of similar P47Rec sequences (leading to high susceptibility) in the invasive An. stephensi may facilitate the gradual emergence of more Pfs47 haplotypes in Africa. However, other genes may also influence the susceptibility of the SDA500 strain. To accurately determine the characteristics of An. stephensi —Plasmodium compatibility in Ethiopia, experimental infections are necessary to validate these hypotheses.