Investigation of the role of Naked 1 in Wnt Signaling
Naked Cuticle 1 (Nkd1) is an obligate Wnt signaling target gene that participates in a negative feedback loop to antagonize Wnt signals. Previous research has shown that Nkd1 interacts with cytoplasmic B-catenin to attenuate the pathway, presumably in cases where the pathway has been over-activated. To validate previous findings, we generated complete nkd1 knockout zebrafish using CRISPR/cas9 and determined that loss of Nkd1 has no phenotypic consequence in zebrafish embryos. The effect of nkd1 loss of function is seen at the molecular level, where qRT-PCR analysis revealed that in cases of excess Wnt signaling, nkd1 -/- mutant embryos had higher expression of Wnt target gene sp5 relative to WT. Immunohistochemistry also revealed that in cases of excess Wnt signaling, nkd1 -/- mutant embryos had higher levels of nuclear B-catenin relative to WT. Based on our findings, we determined that loss of Nkd1 hypersensitizes embryos to Wnt signaling.