Figure 9.

Phylogenetic relationships of class III SLRPs, inferred from the multiple sequence alignment of LRR domains from a reduced set of SLRP sequences (see Methods). The tree has been rooted using the predicted epiphycan-like (EPYL) sequence from lamprey as outgroup. Sequences cluster into three main groups corresponding to class III SLRPs: opticin, epiphycan, and osteoglycins OGN and OGN2. The second copy OGN2 is only present in genomes of ray-finned fishes, whereas the gene for OPTC appears to have largely disappeared from fish genomes, the only known example so far being that of zebrafish. Clade probability values higher than 60% are indicated as in Figure 6. The scale bar represents amino acid substitutions per site.