Different phenotypes of the group-specific component (Gc) in chimpanzees.

The group-specific component (Gc) was examined in a sample of 78 chimpanzees (Pan troglodytes). With isoelectric focusing followed by immunofixation, two different phenotypes are observed. They both differ from the Gc types observed in man. Two alleles are postulated, one coding for a double-band component, the other coding for a single-band component. Neuraminidase experiments indicate the presence of sialic acid in the anodal component of the double-band pattern.