Physical mapping of a family of interferon-activated genes, serum amyloid P-component, and alpha-spectrin on mouse chromosome 1.

This report defines genetic and physical relationships among alpha-spectrin (Spna-1), serum amyloid P-component (Sap), and a family of interferon-activated genes, provisionally designated Ifi202, Ifi203, and Ifi204. By linkage analysis using a large panel of interspecific backcross mice, Sap, Ifi202, and Ifi204 were shown to be tightly linked to Spna-1 on distal mouse chromosome 1. By pulsed field electrophoresis, a genomic restriction map of 6400 kb of distal mouse chromosome 1 was generated, linking genes encoding Sap, (Ifi202, Ifi203, Ifi204), and Spna-1 in that order within 450-1000 kb (where the genes within brackets were not ordered). The interferon-activated genes Ifi202, Ifi203, and Ifi204 were linked within 75-150 kb. Furthermore, genes transcriptionally activated by cytokines, namely Sap, Ifi202, Ifi203, and Ifi204, were located within 450 kb. These studies suggest the possibility that selective pressure may maintain in physical proximity gene clusters which are under coordinate transcriptional control.