Halothane sensitivity and linkage of genes for H red blood cell antigens, phosphohexose isomerase (PHI) and 6‐phosphogluconate dehydrogenase (6‐PGD) variants in pigs*

Abstract
Data from matings appropriate to test linkage in pigs of genes for halothane sensitivity (HAL), H red cell antigens, phosphohexose isomerase (PHI) and 6-phosphogluconate dehydrogenase (6-PGD) red cell isoenzyme variants were consistent with a gene order of Phi-Hal-H-Pgd. There was no unequivocal evidence for a Hal locus separate from Phi, although the phenotype of 1 pig not tested for halothane sensitivity suggested recombination between Hal and Phi. Breeding tests confirmed that in 2 cases there had been recombination between Hal and H. Offspring of 1 of these recombinant types provided evidence for a locus for a gene for inhibition of expression of A and O separate from the locus for H.