Genetic
Basis
One polypeptide-two genes. Both heavy and light polypeptide chains consist of variable and constant regions. There appear to be separate germ line genes for the V and C regions, i. e. the two regions are not inherited as a unit. In both light and heavy chains, identical variable regions may be found on different constant regions and vice versa. One explanation suggested for this is that separate regions of DNA code for the V and C regions of immunoglobulin polypeptides. In other words each polypeptide is coded by two genes located in different regions of DNA.
