We infected Sf9 insect cells with recombinant baculovirus expressing either wild-type DHODH, the two DHODH variants or GFP as background control and analysed the whole cell extracts 72 h after infection for DHODH enzyme activity with 1 mM DHO and 0.1 mM QD (Table 4) as well as for DHODHase expression levels by Western blotting and immunodetection (Fig. 3). This evidence concerns the gene DHODH and infection.