title: Subclustering of human immunoglobulin kappa light chain variable region genes.
abstract: The human immunoglobulin kappa light chain (IgK) locus includes multiple variable region gene segments (Vk) that can be divided into four subgroups. Oligonucleotide primers were designed to amplify specifically gene segments of the VkI, VkII, and VkIII subgroups using the polymerase chain reaction (PCR). Product sequences were subcloned, sequenced, and compared. Phylogenetic analyses of sequences within each subgroup indicate that some subgroups can be subdivided further into "sub-subgroups." The history of Vk segment duplications apparently includes at least two separate periods, the first giving rise to the subgroups and the second generating further complexity within each subgroup. Duplications of large pieces of DNA (demonstrated by others through pulsed-field gel electrophoresis) also played a role. Rates of synonymous and non-synonymous base changes between pairs of sequences suggest that natural selection has played a major role in the evolution of the Vk variable gene segments, leading to sequence conservation in some regions and to increased diversity in others.
authors: Department of Genetics, Stanford University, California 94305.
authors: J H
authors: JH
authors: Kurth
authors: J L
authors: JL
authors: Mountain
authors: L L
authors: LL
authors: Cavalli-Sforza
mesh_terms: D001483:Base Sequence; D005075:Biological Evolution; D017124:Conserved Sequence; D004247:DNA / Q000235:genetics; D015342:DNA Probes; D005803:Genes, Immunoglobulin; D006801:Humans; D007135:Immunoglobulin Variable Region / Q000235:genetics*; D007145:Immunoglobulin kappa-Chains / Q000235:genetics*; D008969:Molecular Sequence Data; D005810:Multigene Family; D009154:Mutation; D016133:Polymerase Chain Reaction
chemical_list: D015342:DNA Probes; D007135:Immunoglobulin Variable Region; D007145:Immunoglobulin kappa-Chains; D004247:DNA