If you have ever lived or worked with me (or are that poor guy who is married to me), then you know that I like things neat and organized. Anything less will send me into a sad tailspin that involves boxed wine and Cheetos. Thankfully, there are enough stunningly beautiful examples of precision, order, and patterning throughout biology to make me happy….like, really happy. Today’s image is from a paper that describes how the different cells in a fruit fly’s eye arrange into the honeycomb pattern seen above.
One of the big questions in developmental biology is how groups of different cell types arrange themselves to form a functional organ. A fantastic model to study this question is the compound fruit fly eye, made of hundreds of ommatidia. A group recently looked at how the several cell types in the developing fly eye are able to reorganize themselves into their honeycomb lattice. The very precise local movements of these cells, according to Johnson and colleagues, require regulation by a protein called Arf6 GTPase in order to connect cell surface signaling with the cytoskeletal rearrangements required for cell motility. The adaptor protein, Cindr, is able to bind to and sequester Arf6 activators called ArfGAPs, which in turn prevents local Arf6 activity. Images above show the precise honeycomb organization in a normal fruit fly pupal eye. In the developing eye (shown chronologically from left to right), the cone cells (orange in cartoon) of each ommatidia are surrounded by a hexagon lattice of cells.
Johnson, R., Sedgwick, A., D'Souza-Schorey, C., & Cagan, R. (2011). Role for a Cindr-Arf6 axis in patterning emerging epithelia Molecular Biology of the Cell, 22 (23), 4513-4526 DOI: 10.1091/mbc.E11-04-0305