Fig. 2
The Tg(ubi:loxP‐ift54‐loxP‐myr‐mcherry,myl7:EGFP)sh488 rescue transgene is recombined after cre mRNA injection, which abolishes its ability to rescue homozygous ift54 tp49 mutants. A: Diagram of the rescue transgene with and without Cre. Cre‐mediated recombination excises WT ift54 and induces mcherry expression. B: Phenotype frequencies in Tg(ubi:loxP‐ift54‐loxP‐myr‐mcherry,myl7:EGFP)sh488 transgenic (+) and nontransgenic (−) embryos from a typical clutch of an ift54 tp49/+;Tg(ubi:loxP‐ift54‐loxP‐myr‐mcherry,myl7:EGFP)sh488 /+ x ift54 tp49/+ cross. Embryos were injected with cre mRNA (+) or uninjected (−). cre injection prevents transgenic rescue. C: Brightfield (top) and fluorescent (bottom) micrographs of 5‐dpf cre mRNA–injected and uninjected embryos from an ift54 tp49/+;Tg(ubi:loxP‐ift54‐loxP‐myr‐mcherry,myl7:EGFP)sh488/+ x ift54 tp49/+ cross. Embryos with the rescue transgene express GFP in the heart. Cre‐mediated recombination prevents rescue of the phenotype and induces mcherry expression. GFP, green fluorescent protein; WT, wild‐type |