Figure 8. Echinoderm Homologs of Human Deaf/Blindness Genes.

The figure depicts the structures of three large membrane proteins encoded in the sea urchin genome, which are orthologs of human genes involved in organization of stereocilia in hair cells of the ear. As described in the text and listed in Table 2, the proteins encoded by these genes are part of an interacting network of membrane and cytoskeletal proteins that organize the stereocilia in the vertebrate ear. Their presence in sea urchins suggests that echinoderms may use a similar interacting network to organize cellular protrusions, perhaps involved in mechanosensation or other sensory functions. The number and position of the repeated FN3 domains in Sp-usherin and Calx_beta in Sp-VLGR are indicated by parentheses and subscripts. For information about the SMART domains presented in this figure, see Suppl. Figure 16.