Murine alpha-fetoprotein and albumin: two evolutionarily linked proteins encoded on the same mouse chromosome.

Several lines of evidence suggest a close functional relationship and a common evolutionary origin for alpha-fetoprotein and albumin. In the mouse, breeding studies have previously allowed the assignment of the albumin gene to chromosome 5. To test the possible linkage of alpha-fetoprotein and albumin, five somatic cell hybrids containing various combinations of mouse chromosomes, together with a constant set of hamster chromosomes, were tested for the presence of both genes using DNA restriction mapping techniques. Two of the five hybrids possessed both genes, and the other three lacked both. The only mouse chromosome present in the positive lines and absent from the negative ones was number 5, allowing the assignment of both genes to this chromosome.