IFT81 mutant in ift81^{hi409tg/hi409tg} background displays ciliary defects: functional assay of the human IFT81 mutation in zebrafish ift81^hi409tg/+ in-crosses. (A) Zebrafish embryos were injected with 50 pg human IFT81-C-Myc-flag or human c.1841T>C-IFT81 mutant-C-Myc-flag mRNA, Western blotting was performed using an anti–C-Myc antibody, β-actin was used as a control (day 0:6 hours after injection; day 1: 28 hours after injection). (B) Bright field images of day 3.5 wild-type like embryo (WT), partial rescued embryo (without kidney cyst but with post-vent increased curvature), and mutant embryo (with postvent increased curvature and kidney cyst; see the arrows and detailed inset in the box). (C) Phenotype distribution of zebrafish embryos injected with 50 pg IFT81 mRNA (WT), IFT81 mutant mRNA (MUT), and noninjected control displaying a significant (***P = 0.0006) reduction in the rescue potential of mutant IFT81 in comparison to WT.