Figure 7
From: Diversity and repertoire of IgW and IgM VH families in the newborn nurse shark
IgW and IgM VH are ancient gene families. A neighbor-joining tree was drawn in PHYLIP using cartilaginous fish and lobe-finned bony fish IgM and IgW VH sequences FR1-FR3 omitting the CDR1-2 from published sources (accession numbers noted next to sample) and this report (identified by clone numbers from Figures 2 and 4). The tree shows the various fish species cluster together by VH family rather than by their evolutionary relatedness indicating the IgW VH gene family is as ancient as the IgM VH gene family.