title: Bovine IgG repertoire is dominated by a single diversified VH gene family.
abstract: Using methods based upon the PCR, we have analyzed sequences that encode the V domain of bovine Ig heavy chain. Pairwise comparison indicates that the heavy chain repertoire in cattle is dominated by a single VH gene family that is homologous to human VHII. The third complementarity-determining region (CDR3) is particularly variable and 60% of the sequences encode a CDR3 in excess of 21 amino acids. Southern blots, single-stranded conformation polymorphism analysis, and sequencing of segments from the germline indicate that the dominant VHII gene family is of small size, comprising as few as 10 unique members, and carries a very low level of diversity in CDRs 1 and 2. Comparison of germline VH sequences with those gathered from adult bovine splenic cDNA demonstrates a pattern of nucleotide substitution that is consistent with diversification through somatic hypermutation.
authors.affiliation: Division of Infection and Immunity, Institute of Biomedical and Life Sciences, University of Glasgow, Scotland.
authors.forename: M C
authors.initials: MC
authors.lastname: Sinclair
authors.forename: J
authors.initials: J
authors.lastname: Gilchrist
authors.forename: R
authors.initials: R
authors.lastname: Aitken
mesh_terms: D000818:Animals; D000916:Antibody Diversity / Q000235:genetics*; D001483:Base Sequence; D002417:Cattle; D018076:DNA, Complementary / Q000302:isolation & purification; D015870:Gene Expression / Q000276:immunology; D005803:Genes, Immunoglobulin; D007074:Immunoglobulin G / Q000737:chemistry / Q000235:genetics*; D007143:Immunoglobulin Heavy Chains / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D007133:Immunoglobulin Joining Region / Q000096:biosynthesis / Q000235:genetics; D007135:Immunoglobulin Variable Region / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D008297:Male; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000276:immunology*; D016415:Sequence Alignment
chemical_list: D018076:DNA, Complementary; D007074:Immunoglobulin G; D007143:Immunoglobulin Heavy Chains; D007133:Immunoglobulin Joining Region; D007135:Immunoglobulin Variable Region