GENOMIC ANALYSIS OF COLLAGEN AND ENDOGENOUS VIRUS LOCI IN THE UCD-200AND UCD-206 LINES OF CHICKENS, ANIMAL-MODELS FOR SCLERODERMA

University of California at Davis (UCD) lines 200 and 206 chickens dev elop a hereditary systemic scleroderma-like connective tissue disease characterized by severe lymphocytic infiltration and excessive accumul ation of collagen in skin and internal organs. The immune system seems to play an important role in the development and/or perpetuation of t his condition. The main goal of our work with this strain is the inves tigation of interactions between endothelial cells, lymphocytes, macro phages and fibroblasts leading to the proliferation of the latter and to excessive collagen synthesis and/or deposition. One aim of the pres ent study was to clarify whether UCD-200 and 206 chickens have a defec t of collagen genes at the genomic level by means of restriction fragm ent length polymorphism (RFLP) analysis using non-radioactively labell ed cDNA probes specific for chicken alpha(1)(I), alpha(2)(I), alpha(1) (II), alpha(1)(III), alpha(1)(VI), alpha(2)(VI), and alpha(3)(IV) (pro )collagens. As in the human disease, no gross alteration at the genomi c level of collagen genes has been found, thus proving the UCD-200/206 model to be appropriate for studying the altered collagen metabolism in systemic sclerosis (SSc). In addition to the RFLP analysis of proco llagen genes, we investigated the endogenous avian leukosis virus loci (ev) of UCD-2O0 and 206 chickens by means of southern blot analysis o f Sac I and BamH I digested DNA samples using pRAV-2, a Rous sarcoma v irus specific probe, for hybridization. Most UCD-200 and 206 chickens harbour evs 1, 3 and 10 similar to the healthy control UCD-058, but th ey also contain a novel ev characterized by a 4.2 kb Sac I fragment an d a 6.1 kb BamH I fragment, which we would like to designate ev 23. So far, the role of eu 23 in the development of avian scleroderma is unc lear; for further analysis classical crossbreeding experiments are nec essary and are underway. (C) 1995 Academic Press Limited