Genetic analysis of 23 RhL-A histocompatibility antigens of the rhesus monkey.

The lymphocytotoxicity of 116 rhesus monkey alloantisera was evaluated in 92 unrelated rhesus monkeys and in 33 pedigreed rhesus families. The study was conducted using a standard complement-dependent microcytotoxocity assay. A computer-assisted chi2 analysis of the reactivity of these sera in unrelated monkeys generated 23 groups of highly correlated antisera. The two-locus model of the mammalian major histocompatibility complex was assumed for the monkey, and genetic criteria for RhL-A antigens were determined before study. Seventeen groups of antisera which had met these predetermined criteria in a previous study using a different random population of monkeys were confirmed in the present analysis. The remaining six groups also met these predetermined criteria, although the genetic data for two were incomplete. Of the 23 antigens defined, 12 appeared to be products of the A locus and 11 of the B locus. Nineteen were similar or identical to antigens previously described by us or by Balner and coworkers in The Netherlands. Two groups have not been previously described. A frequency analysis indicated that these 23 antigens represented approximately 75% of the total expression of the RhL-A-A and RhL-A-B loci.