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 Vλ1-J rearranged combination. The complete coding information of the λ 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 Vλ1 gene. Sequences of somatically rearranged Vλ1 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. © 1987.