Physical mapping of the CXC chemokine locus on human chromosome 4

A physical map of the CXC chemokine locus on chromosome 4 has been constructed by PCR analysis and PFGE mapping of YAC clones. The genes for IL8, GRO1, PPBP, PF4, SCYB5 (ENA-78) and SCYB6 (GCP-2) have been co-localized on a 335-kb genomic fragment. The GRO2 and GRO3 genes did not map within this region and based on analysis of a YAC contig overlapping IL8 we speculate that GRO2 and GRO3 map downstream of this region. We have also assigned the novel CXC chemokine gene, SCYB9B (alias H174/βR1) to chromosome 4q21, upstream and within 12 kb of INP10. Like INP10 and MIG, INP10 and SCYB9B are arranged in a head to tail manner. The chromosomal arrangement of these genes appears to reflect the evolution of this multigene family and supports the theory that it arose by gene duplication.