Gene targeting strategy for B-hCTSG mice.
The exon 1-5 of mouse Ctsg gene that encodes the full-length protein was replaced by human CTSG exon 1-5 in B-hCTSG mice.

Western blot analysis of CTSG protein expression in homozygous B-hCTSG mice. Various tissue lysates were collected from wild-type C57BL/6 mice (+/+) and homozygous B-hCTSG mice (H/H), and then analyzed by western blot with species-specific anti-CTSG antibody. 20 μg total proteins were loaded for western blotting analysis. hCTSG was detected in BM from homozygous mice but not in spleen, thymus,liver and kidney.

Strain specific analysis of CTSG mRNA expression in wild-type C57BL/6 mice and B-hCTSG mice by RT-PCR. BM RNA was isolated from wild-type C57BL/6 mice (+/+) and homozygous B-hCTSG mice (H/H), then cDNA libraries were synthesized by reverse transcription, followed by PCR with mouse or human CTSG primers. Mouse CTSG mRNA was detectable only in wild-type C57BL/6 mice. Human CTSG mRNA was detectable only in homozygous B-hCTSG mice but not in wild-type mice.