cDNA cloning, mapping and polymorphism of the porcine Rhesus (RH) gene

Summary The Rhesus (Rh) gene superfamily in humans and mice contains four independent genes, RH, RHAG, RHBG, and RHCG/GK. Heretofore, only the RHBG cDNA has been cloned in pig. We have isolated the porcine RH cDNA; its complete open reading frame of 1269 nucleotides encoded 423 amino acids. Porcine RH protein shared 67.6% amino acid identity with bovine RH, 61.0% with human RhCE and 60.8% with human RhD. The RT–PCR revealed RH transcripts in the spleen and bone marrow, but not in the heart, kidney, or lung. In RH intron 4, a deletion of 17 nucleotides distinguished the shorter allele (allele 1) from the longer. As determined in 115 unrelated pigs from five breeds – Landrace (L, n = 23), Large White (LW, n = 28), Duroc (D, n = 24), Hampshire (H, n = 20) and Piétrain (n = 20) – allele 1 frequencies were 1.0 (L, H), 0.77 (LW), 0.70 (P) and 0.25 (D). Somatic cell hybrid mapping localized the porcine RH and RHBG genes to pig chromosomes 6q22–q23 and 4q21–q22, respectively. Genetic mapping suggested RH–(FUT1, S, GPI, EAH, A1BG)–PGD as the most probable locus order. Sequence homology, mapping data, and haematopoietic tissue expression suggest that this cDNA may indeed encode the porcine RH homologue.