This ENU-induced mutation was isolated in a screen for recessive vison phenotypes at Northwestern University Center for Functional Genomics. A point mutation, T>C, in the splice-donor site adjacent to exon 12 was identified, disrupting the splice donor site and resulting in skipping of exon 12 and a frame shift creating an early stop codon. The c-terminal region is shorter due to the stop codon and this mutation is predicted to abolish the 4th and 5th transmembrane helices and reverse the orientation of the remaining 3 transmembrane helices. (J:237184)