Polymorphism at the ovine major histocompatibility complex class II loci |
| |
Authors: | A P Escayg J G H Hickford D W Bullock G W Montgomery K G Dodds |
| |
Institution: | Department of Animal and Veterinary Sciences, PO Box 84, Lincoln University, Canterbury, New Zealand;AgResearch Molecular Biology Unit, Department of Biochemistry and Centre for Gene Research, University of Otago, Dunedin, New Zealand;AgResearch, Invermay Agricultural Centre, Private Bag 50034, Mosgiel, New Zealand |
| |
Abstract: | Southern hybridization analysis of the ovine major histocompatibility complex (MHC) ( MhcOvar ) class II region, using sheep-specific probes for the DQA1, DQA2, DQB and DRA loci, has revealed extensive polymorphism. DQA1 and DQAP had eight and 16 alleles respectively, DQB had six and DRA had three alleles. Little information was derived from the DRB locus owing to extensive cross-hybridization between the DRB probe and the DQB locus. Differences in allele frequency between breeds were revealed. At the DQA1 locus a null allele (DQA1-N) was observed with a frequency of between 27% and 45%, making this the most common DQA1 allele in all breeds examined. The frequency of DQA1-N homozygotes was between 11% and 18%, raising questions as to the functional significance of the DQA1 gene. Linkage analysis between the DQA1, DQA2, DQB and DRA loci did not reveal any recombination. |
| |
Keywords: | MhcOvar Ovar-DQA1 Ovar-DQA2 Ovar-DQB Ovar-DRA Ovar-DRB polymorphism |
|
|