Studies on the biosynthetic pathway of human P erythrocyte antigen using genetic complementation tests between fibroblasts from rare p and Pk phenotype donors.

Using the indirect immunofluorescence technique, P antigen is not detected on skin fibroblasts from Pk1, Pk2 or p donors. P antigen is reexpressed on polykaryon cells obtained by fusion of Pk x p fibroblasts. On the contrary, P antigen is not expressed on polykaryon cells from Pk x Pk or p x p fusion. All these data suggest that in Pk and p fibroblasts, at least two distinct genes are modified, one in the p phenotype, and the other in the Pk phenotype. The two Pk phenotypes studied seem to be homogeneous from a genetic point of view, as do the five p phenotypes.