The TRP-1 TCR was generated from immunized Tyrp1B-w mice. Clone 7A6 expressed Valpha3.2Vbeta14 (Vα3.2 and Vβ14) TCR chains. These TCR sequences were cloned into separate vectors and co-injected into microinjected into C57BL/6 fertilized eggs. Founder line 9 was subsequently established and the transgene insertion site was found on the Y chromosome.
The Tyrp1B-w, white based brown mutation was generated in (101/RI x CJH/RI)FI exposed to ionizing radiation and involves the inversion at the 5' end of the tyrosinase-related protein 1 gene. The mice carrying the Tyrp1B-w mutation were backcrossed to the C57BL/6N background for 8 generations.
To generate this triple mutant strain, founder line 9 animals were crossed to mice with the Rag1tm1Mom targeted mutation on the C57BL/6 background. The mice were then crossed to mice carrying both the Rag1tm1Mom and Tyrp1B-w mutations. The strain is maintained hemizygous for the TRP-1 transgene Tg(Tcra,Tcrb)9Rest, homozygous for the targeted mutation Rag1tm1Mom and homozygous for the white based brown radiation induced mutation of tyrosinase-related protein 1, Tyrp1B-w.
A 48 SNP (single nucleotide polymorphism) panel analysis, with 43 markers covering all 19 chromosomes and the X chromosome, as well as 5 markers that distinguish between the C57BL/6J and C57BL/6N substrains, was performed on the rederived living colony at The Jackson Laboratory Repository. One of the 43 markers, on Chromosome 12, was segregating. Also, 2 of the 5 markers that determine C57BL/6J from C57BL/6N were found to be segregating, including the rd8 recessive mutation associated with retinal degeneration on Chromosome 1 within the Crb1 locus. These data suggest the mice sent to The Jackson Laboratory Repository were on a mixed C57BL/6N;C57BL/6J genetic background.
