Fig. 1

Strategy used in the heterologous expression of GP40 and GP15 of Cryptosporidium parvum in Toxoplasma gondii. a The C. parvum GP60 is composed of GP40 and GP15, with a signal peptide at the N-terminus, a GPI anchor at the C-terminus, and a furin cleavage site RSRR between the two cleavage products. In this study, GP40 was truncated and fused to the Twinstrep-6 × HA tag for expression, retaining the signal peptide of GP40 while removing the furin cleavage site RSRR. GP15 without GPI was fused to the 6 × HA tag for expression. b Schematic illustration of the CRISPR/Cas9 strategy used to generate RHΔku80 mutant (Tguprt-Cpgp40 and Tguprt-Cpgp15Δgpi) by inserting CpGP40-Twinstrep-6 × HA-DHFR* (pyrimethamine-resistant DHFR) or CpGP15Δgpi-6 × HA-DHFR*. The transfection of the sgUPRT together with an amplicon containing a CpGP40-Twinstrep-6 × HA-DHFR* (CpGP15Δgpi-6 × HA-DHFR*)-expressing cassette flanked by homology regions to UPRT was used to generate the gene insertion. The orange bar in UPRT gene represents the region targeted by the sgRNA