Integration of gene maps: chromosome 1.

A composite map of 177 loci has been constructed in two steps. The first combined pairwise logarithm-of-odds scores on 127 loci into a comprehensive genetic map. Then this map was projected onto the physical map through cytogenetic assignments, and the small amount of physical data was interpolated for an additional 50 loci each of which had been assigned to an interval of less than 10 megabases. The resulting composite map is on the physical scale with a resolution of 1.5 megabases. In the future these methods may be used to incorporate locations from linkage, contigs, radiation hybrids, restriction fragments, and somatic cell maps. Dense, reliable, and well-documented maps are essential for long-range sequencing and to localize and clone disease genes.