Figure 1.
Cloning and expression of the FCR3.varCSA gene. (A) Overlapping clones of the varCSA gene were isolated from genomic FCR3-CSA parasites and were sequenced. Regions amplified by reverse transcription–PCR from FCR3-CSA trophozoites mRNA confirm that the genomic varCSA gene sequence is contiguous with the exception of the intron region. (B) Schematic domain organization of the FCR3.varCSA gene. An unusually small intron of 230 bp separates exon I and exon II of the varCSA gene. The amino acid boundaries of the different DBL and CIDR-1 domains are indicated. (C) Domain regions that have been expressed on the surface of CHO-745 cells with their amino acid boundaries.