Biochemical characterization of bovine MHC DQ allelic variants by one-dimensional isoelectric focusing.
Previous studies on expressed bovine MHC class II polymorphism using one-dimensional isoelectric focusing (1D-IEF) allowed the identification of at least 12 allelic variants of the DRB3 gene. So far, only limited data have been available on the expression of other class II genes. The present study involved biochemical analysis of bovine MHC class II molecules using a set of monoclonal antibodies presupposed to be bovine DR and DQ reactive. After essential modification of the standard electrophoresis conditions used for 1D-IEF typing of bovine DR products, biochemical polymorphism was observed for non-DR molecules, revealing polymorphic sets of basic and acidic focusing bands. Because of the extensive DNA polymorphism described for bovine DQA and DQB genes, and the apparent similarity with the focusing pattern of human DQ products, these molecules were considered to be the bovine DQ homologues. The definition of the DQ-associated banding patterns was made possible by using two half-sib sire families. Four different DQA-like patterns and nine DQB-like patterns were detected. Segregation of the DQ types was supported by serological class I and class II typing. These results show that it is now possible to discriminate between expressed bovine DR and DQ polymorphism.
Bissumbhar
B
B
Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, University of Utrecht, The Netherlands.
Nilsson
P R
PR
Hensen
E J
EJ
Davis
W C
WC
Joosten
I
I
D000483:Alleles; D000818:Animals; D002417:Cattle / Q000235:genetics* / Q000276:immunology; D015180:Electrophoresis, Gel, Two-Dimensional; D005260:Female; D005802:Genes, MHC Class II; D006239:Haplotypes / Q000235:genetics; D006649:Histocompatibility Antigens / Q000235:genetics*; D007178:Inbreeding; D007525:Isoelectric Focusing; D008297:Male; D011110:Polymorphism, Genetic
D006649:Histocompatibility Antigens