Figure 6
From: Histone variant innovation in a rapidly evolving chordate lineage
O. dioica expresses three H2A.Z N-terminal tail splice variants. A) A common first exon donor site can be alternatively spliced (arrows) to three different acceptor sites in the second exon of OdH2A.Z "GK" splice variant amino acid sequences, resulting in 3 different ORFs encoding 3 H2A.Z sequence variants. Variants, V1 (blue), V2 (light blue) and V3 (dark blue) contained 4, 3 and 2 N-terminal GK motifs, respectively. Compared to H2A.Zs of other species (ci, Ciona intestinalis; hs, Homo sapiens; sp, Strongylocentrotus purpuratus; dm, Drosophila melanogaster; tt, Tetrahymena thermophila), Od and tt H2A.Zs have extended N- and C-terminal tails. OdH2A.Z-specific substitutions in the self-dimerization domain (underlined in yellow, K51-A54), in the α2 helix (S62-S63) and adjacent to the acidic patch (M110) are indicated. B) A 15% acrylamide gel showing the PCR products for the three splice variants, which were excised, cloned and sequenced for confirmation.