title: A hyperconversion mechanism generates the chicken light chain preimmune repertoire.
abstract: The chicken immunoglobulin light chain repertoire has been shown to be entirely derived from a single V lambda 1-J rearranged combination. The complete coding information of the lambda locus was determined: it comprises 25 V-hybridizing elements, all of which are pseudogenes, clustered in both orientations within 19 kb of DNA, starting 2.4 kb upstream of the V lambda 1 gene. Sequences of somatically rearranged V lambda 1 genes from embryonic and posthatching bursal cells show that diversification of light chain sequences occurs during ontogeny by a segmental gene conversion mechanism which takes place at a frequency of 0.05-0.1 per cell generation between the pseudogene pool and the unique rearranged functional V gene.
mesh_terms: D000818:Animals; D000916:Antibody Diversity; D001483:Base Sequence; D002060:Bursa of Fabricius / Q000166:cytology; D002642:Chick Embryo; D002645:Chickens / Q000235:genetics* / Q000276:immunology; D005785:Gene Conversion; D014644:Genetic Variation; D007144:Immunoglobulin J-Chains / Q000235:genetics; D007135:Immunoglobulin Variable Region / Q000235:genetics*; D007146:Immunoglobulin lambda-Chains / Q000235:genetics*
chemical_list: D007144:Immunoglobulin J-Chains; D007135:Immunoglobulin Variable Region; D007146:Immunoglobulin lambda-Chains