ABO Blood groups represent the first described human molecular polymorphism. The ABO gene encodes variants of a protein (a glycosyltransferase) that produces the short sugar chains on glycoproteins and glycolipids that define the A, B, or O antigens. These antigens are found on red blood cells, plasma glycoproteins, and other cell types in various tissues. Individual humans can have one of four blood types based on the two alleles inherited from both parents at the ABO locus: blood type A, B, AB, or O. UC San Diego professor Pascal Gagneux discusses how recent comparative genome studies have revealed that this polymorphic system is ancient and shared between humans and non-human primates, this despite the fact that none of the great ape species carries all four ABO blood types. Series: "CARTA - Center for Academic Research and Training in Anthropogeny" [Humanities] [Science] [Show ID: 37378]