MHC haplotype diversity in the Argos sheep breed from Greece. MHC diversity in Greek sheep

Sheep have been an important part of Greek agriculture for over 5000 years, with hundreds of traditional breeds identified. Many unique characteristics such as tolerance to heat and drought, disease resistance and food conversion are associated with these breeds. Conservation of the unique genetic diversity associated with these breeds is therefore a priority. As part of a study investigating resistance to gastrointestinal nematodes one MHC class II DRB1 allele was divergent from other alleles held within the IPD-MHC database and has been assigned to a new allelic family, Ovar-DRB1*26:01. The full-length DRB1*2601 transcript was identical to alleles in Chinese and Indian breeds and more surprisingly similarity with the bighorn sheep of North America. Extending the class II MHC haplotype analysis to include the DRA, DQA and DQB alleles and MHC class I, we identified a range of novel MHC alleles some of which are also closer to Ovca than Ovar. These data suggest a shared ancestry between Greek, Chinese and Indian breeds and the bighorn sheep.