Assigning the polymorphic human insulin gene to the short arm of chromosome 11 by chromosome sorting.

We have determined the subchromosomal location of the human insulin gene by analyzing DNA isolated from sorted human metaphase chromosomes. Metaphase chromosome suspensions were sorted into fractions according to relative Hoechst fluorescence intensity by the fluorescence activated chromosome sorter. The chromosomal DNA in each fraction was characterized by restriction endonuclease analysis. Initial sorts indicated that the insulin gene-containing fragment resided in a fraction containing chromosomes 9, 10, 11, and 12. Studies of cell lines that contained chromosome translocations permitted the assignment of the insulin gene to a derivative chromosome that contains portions of the short arm of chromosome II. Simultaneous sorting of the normal homolog from this small derivative chromosome separated the two different sized insulin gene-containing restriction fragments in this individual. These data indicate that the two restriction fragments represent insulin gene polymorphism and not duplicate gene loci.