A zebrafish orthologue (whnb) of the mouse nude gene is expressed in the epithelial compartment of the embryonic thymic rudiment.

The cloning and characterization of the zebrafish orthologue of the mouse nude (Whn/Foxn1) gene, whnb are reported. A previously described Whn-like gene from zebrafish, now designated as whna, is shown to be the orthologue of the mouse Foxn4 gene. The whnb gene is specifically expressed in the thymic rudiment of zebrafish embryos at day 3 after fertilization, whereas the whna gene is expressed in eye and brain structures.