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

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 one pig not tested for halothane sensitivity suggested recombination between Hal and Phi. Breeding tests confirmed that in two cases there had been recombination between Hal and H. Offspring of one 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.