Meeting Abstract
Classically, the cephalopod eye is known for its morphological similarity to the vertebrate single-chambered eye. However, this complexity is independently evolved. While vertebrate and fly eye and organ formation have been well studied, little is understood about the coordinated cellular movements that generate complex structures outside of traditional models, like the cephalopod eye. Our interest is to better understand the morphogenesis of complex visual systems in a comparative manner with the goal of revealing basic cellular mechanisms involved in elaborating simple organs into more complicated morphologies. The single-chambered eye of the squid Doryteuthis pealeii is an ideal system to study these processes because eye formation occurs on the exterior of the embryo and is easily visualized. Early in development, the cephalopod eye forms through the internalization of two bilateral retinal placodes by the future lens and iris tissue. This internalization event generates the optic vesicles. These vesicles will eventually grow and develop to generate all the cell types that compose the eye. We have developed in vivo imaging protocols using long-term light-sheet microscopy to better understand tissue movements and cell behaviors during this internalization event. These data highlight how this morphogenetic process differs from other examples of “hole closure” such as Drosophila dorsal closure, wound healing and eyelid closure in mouse. Together this work reveals new insights into epithelial morphogenesis and the generation of complexity found across the Bilateria, and supports the need for broader study of these types of collective cellular mechanisms across the tree.
