The Duffy antigen receptor for chemokines (DARC) is a receptor for both CXC and CC chemokines. We have cloned a mouse gene with a predicted amino acid sequence homology of approximately 63% to human DARC and localized this gene to mouse chromosome 1 between the Xmv41 and D1Mit166 loci. We further demonstrated that, like the human gene, the mouse gene exhibits a single intron of 462 bp which interrupts the open reading frame between the codons for the seventh and eighth amino acid residues. Northern blot analyses revealed that putative mDARC mRNA is highly expressed in adult mouse spleen and skeletal muscle and in whole embryos between embryonic days 8.5 to 12. Northern blot analysis of hemangiosarcomas which develop spontaneously in the spleen of the Eker rat reveal expression of mRNAs which hybridize with both DARC and CXCR2 probes, suggesting a potential role of these receptors in the angiogenesis associated with tumor formation.