This ENU induced mutation has an A to G transition at nucleotide 379 of the cDNA, which alters amino acid 44 from the polar and acidic amino acid glutamic acid into the nonpolar neutral amino acid glycine (Glu44Gly). This amino acid resides in the conserved BTB (Bric-a-brac, Tramtrack, Broad-complex) or POZ (Poxvirus zinc finger) domain of the gene.