Fig. 1

Zebrafish impdh1a transgenic line generation. (A) Two disease-associated IMPDH1 mutations (orange) on IMPDH1 monomer that were stably expressed in zebrafish. (B) Schematic describing the transgenic zebrafish lines. All lines are under a cone transducin promoter, and have a myc tag and a polyA tail. Mutant (K238E or D226N) or wild-type (WT) impdh1a cDNA were injected. (C) impdh1a expression in 7 days post fertilization (dpf) zebrafish larval eyes expressing K238E impdh1a mutation or WT sibling larval eyes. n=3 for K238E and WT siblings. Error bars are s.e.m. (D) impdh1a expression in 7 dpf zebrafish larval eyes expressing K238E impdh1a mutation or WT sibling larval eyes. n=3 for K238E and WT siblings. Error bars are s.e.m. (E) impdh1a expression in 7 dpf zebrafish larval eyes expressing D226N impdh1a mutation or WT sibling larval eyes. n=3 for D226N and WT siblings. Error bars are s.e.m. (F) impdh1a expression in 7 dpf zebrafish larval eyes expressing WT impdh1a or WT sibling larval eyes. n=3 for WT impdh1a and WT siblings. Error bars are s.e.m. (G) Purified Impdh1 protein activity assay. Protein activity in zebrafish with K238E and D226N mutations is not inhibited by high concentrations of GTP (P=9.0×109 for K238E and P=5.0×105 for D226N). Protein activity in zebrafish with K238E mutation is significantly higher at 0.29 mM GTP than for WT Impdh1a protein (P=0.003). n=3 for WT, K238E and D226N. **P<0.005, ****P<0.00005 (unpaired two-tailed t-test). Error bars are s.d. AU, arbitrary units.