The insulin gene is located on chromosome 11 in humans.

Abstract

The polypeptide hormone insulin is required for normal glucose homeostasis. Insulin deprivation results in diabetes, a disease affecting up to 5% of the human population1,2. In some animals there are two insulin genes3; however, in most others, including humans, a single gene is present. The conclusion that there is a single insulin gene in humans is based on the finding of a single insulin species and on genetic studies involving mutant insulin alleles4,5. As the pattern of inheritance of insulin defects is not sex linked, the insulin gene must be located on an autosomal chromosome5. Recently, genomic DNA segments containing the human and rat insulin genes have been cloned and the DNA has been sequenced6–8. The fact that mouse and rat insulins are identical3 suggests that the insulin gene sequences and organization are similar. A knowledge of the restriction endonuclease map for the human and mouse insulin genes enables human or mouse insulin DNA sequences to be distinguished in somatic cell hybrids between the two species. In the present study, somatic cell hybrid gene mapping methodologies9 have been used to determine the chromosome localization10 of the human insulin gene. Human–mouse cell hybrids with different numbers and combinations of human chromosomes were examined for the presence of specific human chromosomes and the human insulin gene using cloned human and rat cDNA probes. A 14-kilobase DNA fragment containing the human insulin gene was present in some cell hybrids and was easily distinguished from the DNA fragments containing the mouse insulin gene found in all cell hybrids. Co-existence of the 14-kilobase fragment and chromosome 11 indicate that the insulin gene resolves on chromosome 11 in humans.