SQUID PAX-6 AND EYE DEVELOPMENT

Pax-6 in vertebrates and its homolog eyeless in Drosophila are known t o be essential for eye development. Here we investigate the role of Pa x-6 in eye development in another major systematic group, molluscs. We demonstrate that alternatively spliced RNAs derived from a single Pax -6 gene in the squid (Loligo opalescens) are expressed in the embryoni c eye, olfactory organ, brain, and arms. Despite significant sequence differences between squid Pax-6 and Drosophila eyeless in the region o utside the paired- and homeodomains, squid Pax 6 is able to induce the formation of ectopic eyes in Drosophila. Our results support the idea that Pax-6 related genes are necessary for eye and olfactory system f ormation throughout the animal kingdom.