Scrib^Crc

A spontaneous mouse mutant that arose in a line carrying a tyrosinase minigene; however, the circletail mutation segregated independently of the transgene. Sequence analysis demonstrated that the coding region contained a single base insertion at codon 947, nucleotide 3182-3 compared with wild-type DNA. The nucleotide insertion is unique to the mutant, and is absent from 16 other mouse strains, including the parental strains on which mutation arose and other unrelated strains. The insertion is predicted to cause a frame shift resulting in a premature termination codon and truncation of the protein to 971 amino acids. Western blot analysis indicates complete absence of the full-length protein in homozygotes and no evidence for a truncated, 100-120 kDa isoform is detected. (J:81365, J:216413)