title: Immunoglobulin gene rearrangements in normal mouse B cells.
abstract: We have analyzed the structure of rearranged mu heavy-chain genes obtained from the genomic DNA of normal BALB/c mouse spleen cells expressing surface immunoglobulin M. Examples were found of two types of nonproductive rearrangements, which may be responsible for allelic exclusion in normal B cells. In one of these rearrangements, a germ line D gene segment has joined to the JH4 gene segment but no V/D joining has occurred. We present evidence that D gene segments lie as a cluster between V and J gene segments in the germ line. A comparison of conserved sequences in V and D gene segments suggests that the D gene segments, which are found only in the heavy-chain gene family, may have evolved from V gene segments similar to the Vk family.
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000502:physiology*; D001483:Base Sequence; D005796:Genes; D007135:Immunoglobulin Variable Region / Q000235:genetics*; D007148:Immunoglobulin mu-Chains / Q000235:genetics; D051379:Mice; D011995:Recombination, Genetic
chemical_list: D007135:Immunoglobulin Variable Region; D007148:Immunoglobulin mu-Chains