The TRE-AblPP transgene was designed with a Tet response element (TRE) followed by a constitutively active c-Abl sequence (AblPP) and a beta-globin polyA sequence. The Tet response element (TRE) contains seven copies of the 42-bp tet operator sequence (tetO) just upstream of a minimal CMV promoter. To generate the AblPP sequence, a cDNA sequence encoding the nuclear-localizing isoform (1b) of the human c-Abl (ABL1; c-abl oncogene 1, non-receptor tyrosine kinase) was modified via site-directed mutagenesis to change the conserved proline residues of the SH2-SH3 linker region to glutamate (P242E/P249E). The 5.4 kb TRE-AblPP transgene was injected into the embryos of FVB/NTac mice. Founder mice were bred with FVB/NTac mice to establish founder line C. The colony was then maintained for several generations by breeding TRE-AblPP females with CaMKIIa-tTA males (on a C57BL/6 genetic background; see Stock No. 007004). During this time, two generations of backcrossing TRE-AblPP males with C57BL/6J females are also reported. TRE-AblPP transgenic mice (not harboring the Camk2a-tTA transgene) on a mixed C57BL/6J;FVB/N genetic background were sent to The Jackson Laboratory Repository (see SNP note below). Upon arrival, TRE-AblPP transgenic mice were bred to C57BL/6J inbred mice (Stock No. 000664) for at least one generation to establish the colony.
A 27 SNP (single nucleotide polymorphism) panel analysis covering all 19 chromosomes and the X chromosome was performed on the rederived living colony at The Jackson Laboratory Repository. 13 of 27 markers (representing 12 different chromosomes) were found to be segregating for allele-type other than C57BL/6. Ten of these 13 markers had the allele-type shared by FVB/NJ and CBA/J. The other three markers (one each on chromosomes 5, 11, and 16) were neither C57BL/6J nor FVB/NJ allele-type, and had the allele-type shared by CBA/J. Taken with the strain development history, these data suggest the mice sent to The Jackson Laboratory Repository are a mix of C57BL/6 and FVB/N, with some remaining CBA genomic contributions left over from the CaMKIIa-tTA breedings.
