March 3, 2011

When I first learned about the elegant experiments of the late Ray Rappaport, I remember feeling like I was having a Zen moment. Amazing things can be learned from some of the simplest experimental designs, and this is a very calming and satisfying concept. Today’s image is from a paper using those same sea urchin eggs that Rappaport used*, and provides us with a great prediction tool for determining how a cell will divide.

Many cells in an embryo must divide in a certain orientation, and many biologists have tried to make predictions on how this orientation is determined. Add the varying shapes a cell may take on within a developing organism, and making these predictions is less than straightforward. In order to make predictions on cell division orientation, a group of biologists set sea urchin eggs into wells of varying shapes. By monitoring the cell division axis in many cells set in wells of many shapes, Minc and colleagues developed a computational model that predicts how the cell division axis is determined for any given shape. Images above show sea urchin embryos in wells of different shapes.

Minc, N., Burgess, D., & Chang, F. (2011). Influence of Cell Geometry on Division-Plane Positioning Cell, 144 (3), 414-426 DOI: 10.1016/j.cell.2011.01.016
©2011 Elsevier Ltd. All rights reserved.

* Correction: Rappaport didn't use sea urchin eggs. In most of his experiments, he used a different echinoderm--the sand dollar. Thanks to Bob G. for the note!