SKIN ALLOGRAFT SURVIVAL IN CHICKEN STRAINS WITH SPONTANEOUS AUTOIMMUNE-DISEASES

Skin grafts were performed to prove the level of genetic diversity in chicken populations of the Obese strain (OS), which develops a spontan eous Hashimoto's-like thyroiditis, and University of California at Dav is (UCD) Line-200 chickens, which are hereditarily afflicted with prog ressive systemic sclerosis (scleroderma). As controls, Cornell C-strai n (CS) and inbred, normal White Leghorn CB chickens were included in t he genetic monitoring program. At the commencement of this study in 19 88, median allograft rejections were observed after 9 to 12 d (range 8 to 14 d) in OS and CS chickens that derived from large flocks at Corn ell University, whereas OS sublines of the smaller, more closely-bred colonies at the University of Innsbruck, Austria, showed median allogr aft rejection after 19 d (range 12 to 35 d). From 1988 to 1993, allogr aft survival was only slightly prolonged in the OS sublines. However, the results of the skin allotransplantations in inbred UCD-200 chicken s revealed two subpopulations in this line. In one subgroup the median of allograft rejection was calculated with 13 d (range 6 to 37 d) in 1989, 30 d (10 to 37 d) in 1990, 21 d (8 to 90 d) in 1991, and 16 d (7 to 26 d) in 1993. In the other subgroup allografts were accepted at r ates similar to autografts. In addition, the inbreeding coefficient wa s calculated for eight male and eight female OSB(5)B(5)Cornell (C) and OSB(5)B(5)Innsbruck (INN) chickens, respectively, hatched in 1993. On the basis of mating records, the minimal estimate of the inbreeding c oefficient was calculated to be 0.0679 in the (OSBBC)-B-5-C-5 and 0.10 35 in the (OSBBINN)-B-5-I-5 population. The results demonstrated a hig her degree of consanguinity in the smaller population of (OSBBINN)-B-5 -I-5 chickens compared to (OSBBC)-B-5-C-5 birds. The latter are mainta ined in larger numbers, therefore, the frequency of matings between re lated individuals should be lower.