Polymorphism of adenosine deaminase in the pig: allelic variation eruthrocytes

Two new common alleles of erythrocyte adenosine deaminase (ADA) in pigs

New adenosine deaminase variants ADA C and ADA D were found by means of agarose gel electrophoresis in pig erythrocytes. Family data supported the hypothesis that these are controlled by codominant alleles ADAC and ADAD. The ADAC allele was present in Large White (q = 0.076), Landrace (q = 0.037) and their crosses with other breeds. The ADAD allele was present in Duroc (q = 0.067) and its crosses. Allele frequencies for six pig breeds are given.

Adenosine deaminase in the pig: tissue-specific patterns and expression of the silent ADA0 allele in nucleated cells

By means of polyacrylamide gel and cellulose acetate enzymo-electrophoresis, the authors have studied tissue-specific isozymes of adenosine deaminase in the pig; these have been correlated to the erythrocytic ABO-like polymorphism. The enzyme product of the ADA0 gene was detected in nucleated cells; the absence of the ADA0 gene product in erythrocytes was tentatively accounted for by an increased in vivo lability.

Note on a third allele in the erythrocytic NP system of cattle

A bull ('Mercure') with an erythrocytic NP (nucleoside phosphorylase), phenotype showing a slightly higher anodal mobility has been found. His progeny data generally support the hypothesis of a third F allele in addition to the more common S and the L alleles, resulting in an ABO-like system.

Inheritance of adenosine deaminase variants in chickens and turkeys

Blood cell lysates of chickens and turkeys were subjected to starch gel electrophoresis and the gels were stained for adenosine deaminase. Two zones were observed singly or together in the electrophoretic patterns of each lysate. Zones of chicken lysates were analogous in electrophoretic mobility to those of turkeys. An extra zone which appeared in patterns of a sample stored over one month was not detected in patterns of a second aliquot of stored sample treated with a reducing agent prior to electrophoresis. Family data involving 110 chicken progeny and 221 turkey progeny supported the hypothesis that these zones were controlled by two codominant alleles designated ADAA and ADAB. In the two Leghorn strains studied ADAB was much more frequent than ADAA, but the frequency distribution was reversed in the Small White turkey strain examined.

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.

Is inosine the physiological energy source of pig erythrocytes?

Pig erythrocytes are unable to metabolize glucose and their physiological energy source is unknown. These cells have a high-capacity nucleoside transport system with similar properties to that responsible for nucleoside transport in other species. Nucleoside transport is sufficiently rapid to allow the possibility that inosine and/or adenosine may represent major energy substrates for pig erythrocytes in vivo. Normal and adenosine deaminase-deficient pig erythrocytes have similar ATP levels, suggesting that adenosine is not important in this respect. However, it was calculated that an extracellular inosine concentration of only 40 nM could support the cells' entire energy requirement, a value 40-fold lower than plasma levels of this nucleoside.