Fig. 1: Role of Serine/Threonine protein kinase (Pfstk2) in gametocytogenesis.

a Gametocyte conversion rate (GCR) of 3D7.stk2Δ clones (B4, F6) and the parental line (3D7). b Day 6 thin smear of n-acetylglucosamine treated cultures showing the presence or absence of gametocytes (arrows) in the parent 3D7 and 3D7.stk2Δ clone (B4), respectively. c Ap2-g expression fold changes in ring stage parasites from NF54, 3D7, 3D7.stk2Δ clones (B4, F6), ap2-g truncated line F12, and NF54.gdv1.3xha.fkbp in the absence (GDV1-) or presence (GDV1 + ) of Shld1. d GCR phenotype of the parent NF54 and STK2 inducible NF54.stk2.gfp.fkbp clones (A, B & C) in the presence (+) or absence (-) of Shld1. e GCR phenotype of the parent NF54 and NF54.stk2Δ clones (D, E & F). f Ap2-g mutation (g.6487 G > T) resulting in p.V2163L amino acid substitution was present in all the sequence reads from the 3D7.stk2Δ line (gray bars). The 3D7 reference sequence is shown at the bottom just above the corresponding amino acid sequence in all 3 reading frames. The arrow indicates the third reading frame encodes AP2-G. g Protein sequence alignment of the AP2-G AP2 domain derived from five diverse malaria parasite species, P. vivax (Pv), P. knowlesi (Pk), P. falciparum (Pf), P. berghei (Pb) and P. yoellii (Py), indicates conservation of the mutated valine (black box). h Schematic of AP2-G (aa 1 - 2432) with the AP2 DNA binding domain indicated by a green box and SNPs previously identified in the ap2-g locus in lab-adapted lines (red arrow), the present study (red dotted arrow) or field isolates (diamonds²²). For graphs (a, c–e) independent data points are indicated by circles and the bar and error bar represent the mean and standard error of the mean, respectively. a, d, e experiments were performed in biological triplicates and repeated independently thrice whereas in (c) experiments were repeated independently 7 times for the parental 3D7, 8 times for clone B4, 7 times for clone F6, 4 times for F12 and 3 times for NF54 and GDV1 (+/-). A Mann-Whitney test (a, c) or Kruskal-Wallis test followed by Dunn’s multiple comparison (d, e) was used for statistical analysis between groups/conditions. The groups compared were parental wt vs stk2Δ clones (a), wt vs mutant ap2-g (c, d), intact (+) or knocked down stk2 (-) (d), or parental wt vs knocked out stk2 (e). Source data are provided as a Source Data file.