Figure 1. Schematic representation and alignment of wild type and transgenic P.berghei circumsporozoite proteins.

(A) Schematic representation of the CS proteins present in each of the four transgenic P. berghei parasite lines generated. The corresponding names of the transgenic parasite lines are shown on the right. PbCS^DHFR parasites carry the wildtype PbCS coding sequence (white boxes, RI and RII indicated with light and dark green respectively) and, similar to all transgenic lines, contain the T. gondii DHFR drug selectable marker inserted in the CS locus. PgCS^SX parasites carry the full PgCS coding sequence (grey boxes, RI and RII indicated with light and dark blue respectively), but with the SpeI (S) and XhoI (X) restriction endonuclease sites inserted on either side of the repeat region. PgCS/Pb^RR parasites contain the PgCS N-terminal and C-terminal regions (grey boxes) and the PbCS repeat region (white box). PbCS/Pg^CT parasites carry the PbCS N-terminal and repeat regions (white boxes) and the PgCS C-terminal region (grey box). (B) Alignment of the wild type PbCS and transgenic PgCS^SX and PgCS/Pb^RR amino acid sequences. Shaded boxes represent areas of amino acid identity. Regions I and II (black lines), the repeat region (blue line) and the SpeI and XhoI restriction sites (red lines) are labelled. The SpeI and XhoI sites were introduced into the PgCS sequence to mediate exchange of the PgCS repeat region with the PbCS repeat region.