Figure 5

(A) We generated 2 zebrafish lines containing human cDNA for JAK1-WT (JAK1^WT) and JAK1-A634D (JAK1^GOF). Ubi is a ubiquitous promoter driving expression of JAK1 and the green fluorescent protein (GFP). Constructs were microinjected into 1-cell stage zebrafish embryos. GFP⁺ fish were selected. (B) Different doses of ruxolitinib were tested to determine the optimal dose for the survival for both transgenic fish lines. Ruxolitinib (1 ?M) was selected based on higher survival levels for all 3 transgenic lines. Survival was compared between groups (JAK1^WT and JAK1^GOF transgenic and uninjected zebrafish) (P < 0.0001) and was also compared across varying doses of ruxolitinib in JAK1^GOF transgenic zebrafish (P < 0.0001) using 2-way repeated-measures ANOVA. (C) F1 embryos from JAK1^GOF founders with transgene expression exhibited abnormal development, which was rescued upon exposure to ruxolitinib, revealing a conserved functional developmental impact of JAK1^GOF in the zebrafish. The remaining percentages correspond to GFP-negative zebrafish. (D and E) Representative pictures of 30 hpf JAK1^GOF-injected zebrafish, with normal and abnormal development.