Further data on adenosine deaminase polymorphism in pigs and evidence for a new allele

Evidence was provided for a new erythrocyte ADA allele (Aw) in the Swedish Landrace breed of pigs. The enzyme activity of Aw variant was considerably less than that of the previously reported erythrocyte ADA variants A and B. The mobility of the Aw variant was identical to that of the A variant, both by electrophoresis and by isoelectric focusing. The in vitro heat stability (at 56 degrees C) of the Aw variant was similar to that of A and B variants. The leucocyte ADA activity was normal in pigs with the erythrocyte ADA Aw variant. The frequencies of the erythrocyte ADA alleles, A, B, Aw, and O (silent allele) in four breeds of pigs in Sweden were: Landrace--0.51, 0.19, 0.11, 0.19; Large White--0.91, 0.03, 0.0, 0.06; Duroc--0.95, 0.05, 0.0, 0.0; Hampshire--0.12, 0.14, 0.0, 0.74.