Loss of the six3/6 controlling pathways might have resulted in pinhole-eye evolution in Nautilus.

ABSTRACT: Coleoid cephalopods have an elaborate camera eye whereas nautiloids have primitive pinhole eye without lens and cornea. The Nautilus pinhole eye provides a unique example to explore the module of lens formation and its evolutionary mechanism. Here, we conducted an RNA-seq study of developing eyes of Nautilus and pygmy squid. First, we found that evolutionary distances from the common ancestor to Nautilus or squid are almost the same. Although most upstream eye development controlling genes were expressed in both species, six3/6 that are required for lens formation in vertebrates was not expressed in Nautilus. Furthermore, many downstream target genes of six3/6 including crystallin genes and other lens protein related genes were not expressed in Nautilus. As six3/6 and its controlling pathw

SUBMITTER: Ogura A 

PROVIDER: S-EPMC3594755 | biostudies-literature | 2013

REPOSITORIES: biostudies-literature