Comparison of vertebrate HoxD13 protein sequences. (a) Diagram of the structure of HoxD13 gene. The HoxD13 gene comprises two exons (shown as open boxes), and the homeobox region locates in the exon2 (indicated by dash line frame). (b) Partial protein alignment of HoxD13 (shaded region in Figure 4a) from human (Homo sapiens), mouse (Mus musculus), chicken (Gallus gallus), frog (Xenopus tropicalis), lungfish (Protopterus annectens), elephant shark (Callorhinchus milii) and zebrafish (Danio rerio). Exon-intron splicing site is indicated as black triangle and the homeobox region is shown in a dash line frame. (c) Neighbor-joining tree (JTT distance) inferred from the above protein alignment with bootstrap supports of 1,000 iterations.
Liang et al. BMC Evolutionary Biology 2011 11:25 doi:10.1186/1471-2148-11-25