Fine mapping of autoimmune diseases in chicken

Abstract: Autoimmune diseases arise due to tolerance breakdown or failure of the body's immune system to establish tolerance leading to the body failing to recognize its own tissues and organs as self. Systemic sclerosis is a disease of the connective tissue characterized by immunological abnormalities and increased deposition of extracellular matrix proteins in the skin. Vitiligo is a dermatological disorder characterized by loss of melanocytes from the cutaneous epidermis. The aim of this project was to confirm the previously identified QTLs in the Smyth line (SL) chicken model of vitiligo in F3-F5 generations of the SL and Brown line (BL) cross and systemic sclerosis in the University of California at Davies (UCD 200) model in the 2nd backcross generations (BC2) of UCD 200 and red jungle fowl cross (RJF). We confirm the association of the disease with our marker genotypes on chromosome 3 but not on chromosomes 9 and 21 in the SL and BL crosses from F3-F5 generations. We did not confirm the disease association with chromosomes 2, 12, 14 and 19 in the BC2 generation from the UCD x RJF cross because the pedigree was not large enough for the analysis. 68% of the individuals in the BC2 pedigree expressed the diseases with males showing 100% liability. We recorded a mortality rate of approximately 50% in the BC2 population. We did not observe any significant mortality in the intercrosses between the SL and BL.