(A) Dendrogram and (B) CDR3 alignment of anti-Rh(D) heavy chains. The 28 unique heavy chain clones are organized by V_H family, V_H germline gene, and VDJ rearrangement. Each heavy chain clone is identified by a numeral preceded by a letter (B through E) that denotes its germline gene. The 28 heavy chains comprised 12 distinct VDJ regions, designated VDJ1 through VDJ12. Clones with identical VDJ joins putatively result from intraclonal diversity of 12 original B lymphocytes.