Summary. The Third International Workshop on Lymphocyte Alloantigens of the Horse was held on 25–27 April 1984 in Kennett Square, Pennsylvania. Twelve laboratories from five countries participated. The principal purpose of this Workshop was to determine the phenotypic and gene frequencies of the 10 equine lymphocyte antigens (ELA) and a non‐ELA lymphocyte antigen, ELY‐2.1, in several breeds of horse. A total of 86 alloantisera characterized in previous workshops were tested against lymphocytes from 1179 horses. In addition, several experimental antisera were also tested against the same panel of lymphocytes. As a result of analysis of these data, the Workshop recognized two new equine lymphocyte alloantigens: W11 of the ELA system, and ELY‐1.1, an antigen not linked to the ELA system.

Summary. The workshop consisted of 12 monthly cell exchanges of full‐sibling families among the 10 participating laboratories. A total of 33 parents, 52 offspring and five unrelated horses were typed by each laboratory using local antisera. The raw data were submitted for central analysis before any identification of the animals was revealed. Confidence derived from the consistent agreement between the laboratories on the assignment and segregation of the first 10 ELA‐W specificities led to the removal of the W (workshop) notation and acceptance of full status as locus A antigens. The seemingly supertypic W11 specificity, however, remained unchanged. Ten additional specificities were seen to segregate with the ELA system, suggesting either splits of previously described specificities or products of linked loci. The workshop (W) notation was given to the 10 specificities W12‐W21, befitting their status as specificities under study. The previously described ELY‐1.1 specificity, characterized by segregation independent from the ELA system, was confirmed along with a new specificity, ELY‐1.2, which behaves as an allele of ELY‐1.1. For informative families, the two specificities showed codominant expression and appeared to constitute a closed, autosomal system. The ELY‐2.1 specificity was confirmed to segregate independently from the ELA‐A and ELY‐1 loci.

No abstract

No abstract

Evidence is presented for close genetic linkage between the structural loci for serum albumin and the vitamin D binding protein (Gc) in Belgian Blue and White cattle. Five recombinants were observed in a total of 342 informative offspring. The recombination frequency between the two loci was estimated as 1.5% k 0.9. The observed distribution of the haplotypes deviated from the expected one in the population, probably due to selection and significant linkage disequilibrium.