Hh blood group final step in the synthesis of the molecule. Depending upon a person's ABO blood type, the H antigen is converted into either the A antigen, B antigen, or both. If a person has group O blood, the H antigen remains unmodified. Therefore, the H antigen is present more in blood type O and less in blood type AB. Two regions of the genome encode two enzymes with very similar substrate specificities: the H locus (FUT1) which encodes the Fucosyl transferase and the Se locus (FUT2) that instead indirectly encodes a soluble form of the H antigen, which is found in
Blood type (non-human) systems, respectively. Two blood group systems have been defined in Old World monkeys: the Drh system of macaques and the Bp system of baboons, both linked by at least one species shared by either of the blood group systems. Over 13 canine blood groups have been described. Eight DEA (dog erythrocyte antigen) types are recognized as international standards. Of these DEA types, DEA 4 and DEA 6 appear on the red blood cells of ~98% of dogs. Dogs with only DEA 4 or DEA 6 can thus serve as blood donors for the majority of the canine population. Any of