The allograft reaction as an index of genetic diversity in inbred chickens.

The main purpose of the study was to use the skin allograft reaction as a possible biological tool to estimate genetic diversity (inbreeding) in a population and to determine the relative influence on the B locus blood group locus on variation in graft rejection. In chickens, the B locus is the major histocompatibility system. One outbred and five inbred lines were used in 12 skin grafting experiments. Graft exchange also were made between certain line crosses. The study was based on 2172 allografts performed on 712 chickens.Incompatibility of the B blood group locus accounted for 3/4 of the total variance in homograft rejection within lines. For the compatible allografts only, lines accounted for more than 90% of the total variation.Graft acceptance in terms of mean survival time (MST) was highest in the most highly inbred lines and lowest in the noninbred control. The regression of genetic diversity, as a function Wright's inbreeding coefficient, as a percentage of allograft rejection may be a useful biological index of genetic diversity.