Gene targeting strategy for B-hGPR40 mice. The exon 1 of mouse Gpr40 gene that encodes the full-length protein was replaced by human GPR40 exon 1 in B-hGPR40 mice.

Western blot analysis of Gpr40 protein expression in homozygous B-hGPR40 mice. Various tissue lysates were collected from wild-type C57BL/6 mice (+/+) and homozygous B-hGPR40 mice (H/H), and then analyzed by western blot with specific anti-GPR40 antibody. 20 μg total proteins were loaded for western blotting analysis. hGPR40 was detected in pancreas from homozygous mice but not in liver, kidney and stomach. The antibody is cross-recognized between humans and mice.

Strain specific analysis of GPR40 mRNA expression in wild-type C57BL/6 mice and B-hGPR40 mice by RT-PCR. BM RNA was isolated from wild-type C57BL/6 mice (+/+) and homozygous B-hGPR40 mice (H/H), then cDNA libraries were synthesized by reverse transcription, followed by PCR with mouse or human GPR40 primers. Mouse Gpr40 mRNA was detectable only in wild-type C57BL/6 mice. Human GPR40 mRNA was detectable only in homozygous B-hGPR40 mice but not in wild-type mice.