The following is an example of additional strain background information:

The original mutation was ENU-induced on a (C3H/HeJ x BALB/c)F1 and backcrossed to C3H/HeJ for linkage testing. The mutation is maintained by continual backcrossing to C3H/HeJ. The phenotypes reported were observed in the N1-N5 generations, with no differences noted among the generations typed.