Ctse^{C57BL/6JOlaHsd}

This variant confers at least 8-fold lower expression of cathepsin E mRNA in spleen and of CTSE protein in spleen-derived leukocytes, as determined by semiquantitative PCR and immunoblot analysis, respectively, than does the 129S/SvHsd variant. Flow cytometry combining cell-surface markers with intracellular detection of CTSE demonstrates >80% lower CTSE Median Fluorescent Intensity (MFI) in B and T lymphocytes, macrophages and dendritic cells from spleens or peripheral blood of C57BL/6JOlaHsd than of 129S/SvHsd mice. High and low expression levels segregate with homozygosity for the 129S/SvHsd and for the C57BL/6JOlaHsd Ctse variant (genotyped based on an SspI RFLP due to a SNP in intron 5), respectively, in F2 progeny of intercrosses between these two strains. The reported sequence of the Ctse promoter region in C57BL/6J (NCBI Ref. Seq. NT_078297.7) differs from those of both BALB/cOlaHsd (J:128538) and 129X1/SvJ (GenBank: Y10928.1) by a G-to-A transition 64 nucleotides (nt) from the start of transcription that abrogates a reportedly functional SFPI1 (PU.1) transcription factor binding site (GAGGAA --> GAGGAG); the C57BL/6J promoter sequence shares with BALB/cOlaHsd a G-to-A transition 30 nt from the transcription start site that disrupts a putative ETV4 (PEA3) consensus binding sequence. (J:128538)