X-ray radiation mutagenesis induced a mutation in the pink-eyed locus that compliments Gabrb3Cp1. Deletion with proximal breakpoint between D7Mit193 and D7Mit145; distal breakpoint between Gabrg3 and D7Cwr15. However, the interstititial sequences D7Mit232, D7Mit18, D7Mit83 are not deleted. (J:12553, J:100221)