Within the frame of our investigations on genetic variation of pig red cell enzymes, by means of enzymo-electrophoresis and spectrophotometric measurements, four kinds of adenosine deaminase phenotypic patterns were identified in haemolysates from 542 Belgian Landrace and 502 Pietrain pigs. Segregation data are consistent with the hypothesis that these phenotypes are determined by two codominant alleles ADAA and ADAB and a recessive silent allele ADAO, at an autosomal locus. Differences in gene frequencies between the two breeds are highly significant.

SummaryAn electrophoretic survey of 13 enzymes corresponding to 19 loci has been carried out in Belgian Landrace and Pietrain pig breeds. Four of these enzymes have been shown to exhibit electrophoretically detectable polymorphism. The average heterozygosity per locus was found to be 0.066 in the Belgian Landrace and 0.028 in the Pietrain pigs.

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.