The Catb allele arose in the randomly mated progeny of a male that had been exposed to X-irradiation at Oak Ridge National Laboratory. The male was an F1 from a cross between 101 and C3H. He was bred to a female from a recessive test stock that was homozygous for the following seven alleles: a, Tyrp1b, Tyr c-ch, p, Myo5ad, Bmp5se, and Ednrbs. This test stock was derived from the breeding of NB stock, which contained the first six alleles, with a non-inbred stock that was homozygous for Ednrbs and three of the other six alleles (Russell, WL, 1951. Cold Spring Symp. Quant. Biol. 16, 327-336). A female was identified with a blood catalase level of 40 PU/ml. She was bred to a wild type male and the offspring also had lower than normal blood catalase activity. One of these F1 males was backcrossed to its mother and a strain described as acatalasemic derived from this. While the history of this strain began at Oak Ridge National Laboratory, it moved to RN Feinstein at The Argonne National Laboratory and was backcrossed to C3HfB/Anl for 8 generations, reaching N8 in approximately 1968, and was then inbred. It was transferred from RN Feinstein to Allen H. Gates at The University of Rochester in 1975 when it was at N8F13. In 1986 this strain was at N8F13+30. The N8F13+44 generation of this strain was received by The Jackson Laboratory in July, 1991 from Allen H. Gates. It was sibling mated and frozen as embryos at N8 F13+44+2. (Gates, AH, Mouse News Lett. 1987. 79:17)
