title: Organization and genomic complexity of bovine lambda-light chain gene locus.
abstract: Complete characterization and physical mapping of bovine lambda (lambda) light chain locus, spanning 412kbp, on chromosome 17, has revealed twenty-five V(lambda) genes, seventeen being functional, organized in three sub-clusters 23.7kbp 5' of the J(lambda)-C(lambda) units. Three V(lambda) sub-clusters are separated by two large introns of 126.8 and 138.3kbp. The predominantly expressed V(lambda)1 genes are present in the two 5' sub-clusters, while J(lambda)-proximal V(lambda) sub-cluster comprises rarely expressed V(lambda)2 and V(lambda)3 genes. The preferential expression of V(lambda)1 genes in the bovine immunoglobulin repertoire is influenced by the composition of recombination signal sequences (RSS). Of the J(lambda)-C(lambda) cluster, it is mainly J(lambda)3-C(lambda)3 unit that is expressed in reading frame 2, though J(lambda)2 and J(lambda)3 have identical RSS. The predominant expression of J(lambda)3-C(lambda)3 genes over J(lambda)2-C(lambda)2 is likely due to endogenous counter selection for J(lambda)2 encoded CDR3 and framework 4 regions. Differences in the genomic complexity of V(lambda) genes in Hereford and Holstein cattle are due to polymorphism at the lambda-light chain gene locus. Despite more potential germline encoded combinatorial diversity, restricted V(lambda)1-J(lambda)3-C(lambda)3 recombinations encode the most lambda-light chain repertoire in cattle.
authors.affiliation: Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada N1G 2W1.
authors.forename: Yfke
authors.initials: Y
authors.lastname: Pasman
authors.forename: Surinder S
authors.initials: SS
authors.lastname: Saini
authors.forename: Elspeth
authors.initials: E
authors.lastname: Smith
authors.forename: Azad K
authors.initials: AK
authors.lastname: Kaushik
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000916:Antibody Diversity; D001483:Base Sequence; D002417:Cattle / Q000235:genetics* / Q000276:immunology*; D004247:DNA / Q000235:genetics; D020224:Expressed Sequence Tags; D015870:Gene Expression; D015328:Gene Rearrangement, B-Lymphocyte, Light Chain; D050439:Genes, Immunoglobulin Light Chain; D007146:Immunoglobulin lambda-Chains / Q000235:genetics*; D008969:Molecular Sequence Data; D005810:Multigene Family; D010802:Phylogeny; D020161:Physical Chromosome Mapping / Q000662:veterinary; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity
chemical_list: D007146:Immunoglobulin lambda-Chains; D004247:DNA