Identification of new major histocompatibility complex class II restriction fragment length polymorphisms in a closed experimental line of Beltsville Small White turkeys

Respiratory Diseases of Livestock Research Unit, National Animal Disease Center, USDA Agricultural Research Service, Ames 50010, USA. rsacco@nadc.ars.usda.gov

Beltsville Small White (BSW) turkeys have been utilized as an experimental model in the study of bacterial, parasitic, and fungal diseases. Given the critical role of MHC antigens in the initial steps of the immune response to specific pathogens, the MHC Class II of BSW turkeys was characterized. Southern blot analysis of PvuII-digested turkey DNA that was hybridized with a chicken Class II beta gene genomic clone revealed two restriction fragment length polymorphism profiles not previously identified in experimental or commercial breeder lines of turkeys. These fingerprint profiles differed in a single 6.0-kb band that was present in approximately 38% of the birds examined. The DNA fragments of 5.0, 4.1, 3.3, and 3.1 were present in both profiles. Furthermore, no mixed lymphocyte reaction was observed between individuals within the BSW turkey line. The present results indicate that BSW turkeys represent a unique source of genetic diversity for MHC Class II haplotypes.