Definition of 15 equine leucocyte antigens

Fifteen equine leucocyte antigens were defined by absorption and titration analysis of alloantisera obtained by natural sensitisation through pregnancy and by planned experimental immunisation. Definitive sera were tested on the cells of 90 unrelated horses and members of eight equine families. The family data suggested that 13 specificities were coded by a single locus (first locus) and one specificity (Eq 14) was coded by a second linked locus. The remaining specificity (Eq 7) was controlled by a third locus unlinked to the first or second loci. Tests on the cells of unrelated horses showed that two first locus specificities (Eq 16 and Eq 17) had a supertypic relationship to other first locus antigens. No individual was found to possess more than two first locus antigens, excluding the supertypic specificities.