This ENU-induced mutation was isolated in a screen at the University of Pittsburgh. The molecular lesion is a T to A substitution at nucleotide +2 after coding nucleotide 438 (c.438+2T>A, NM_133365) in intron 4. This changes splice donor site G-GT to G-GA (which is assumed to be inactive). (J:175213) Additional incidental mutations were detected in sequencing for the causative mutation, Dnah5b2b601Clo, and may be present in stocks carrying this mutation.