Gene targeting strategy for B-hCSF1 mice. The exon 2-8 of mouse Csf1 gene that encodes the full-length protein was replaced by human CSF1 exon 2-8 in B-hCSF1/CSF1R mice. The promoter, signal peptide, 5’UTR and 3’UTR region of the mouse gene are also retained. The chimeric CSF1 expression is driven by endogenous mouse Csf1 promoter, while mouse Csf1 gene transcription and translation will be disrupted.

Strain specific CSF1 expression analysis in heterozygous B-hCSF1 mice by ELISA.
Splenocytes were collected from WT mice and heterozygous B-hCSF1 mice (H/+) stimulated with LPS in vivo, and analyzed by ELISA with species-specific anti-CSF1 ELISA kit. Mouse CSF1 was detectable in WT mice and heterozygous B-hCSF1 mice. Human CSF1 was exclusively detectable in heterozygous B-hCSF1 mice but not in WT mice.