Figure 1.

HoxA clusters for human (Hs A), horn shark (Hf M), zebrafish (Dr Aa), and zebrafish (Dr Ab) are drawn schematically. Coding regions of each gene on a cluster are represented by dark blue squares. For human and horn shark only, the region spanning from hoxa7 to hoxa4 is enlarged. Phylogenetic footprint clusters (PFCs) within each intergenic region share the same geometric shape; letters above shape are as found in Table 1. Note that except for the region between hoxa7 and hoxa4, the only PFCs shown are those that are present in human and/or horn shark as well as at least one of the zebrafish clusters. PFCs shared between human and horn shark are red shapes. A red shape with an asterisk designates a PFC that is found only in human or horn shark. PFCs on the zebrafish HoxAa cluster that are homologous to horn shark and/or human are magenta shapes. PFCs on the zebrafish HoxAb cluster that are homologous to horn shark and/or human are light blue shapes. PFCs shared only by zebrafish HoxAa and HoxAb clusters or by at least one zebrafish cluster and the HoxA cluster of striped bass (Table 1) are yellow shapes. PFCs shared by all four clusters (taxa) are green shapes. See text and Table 1 for description. The line indicates distance in kilobases (kb).