Rearranged immunoglobulin heavy chain variable region (VH) pseudogene that deletes the second complementarity-determining region.

Abstract

Two rearranged H chain variable region (VH) genes were cloned from the IgG-producing human cell line CESS. The VH gene, which is linked to the .mu. chain constant region (C.mu.) gene, has 2 deletions at residues 45-62 and 82A-90, the former of which corresponds closely to the 2nd complementarity-determining region (CDR2). Translocation of CDR2 apparently occurred and could give support to the argument that reassortment of the V minigenes is involved in the generation of hypervariability during evolution. The rearranged pseudogene could have also arisen by fortuitous deletion. The other VH gene of CESS is an expressed form and is probably linked to the C.gamma. gene. The diversity region (D) segments used in these rearranged V. genes are < 38% homologous to known human germline D segments, indicating the presence of more unknown germline D segments.