Time for some biology! I just saw this paper which deals with a subject I enjoy reading about:

DOI (still in advance publication): 10.1126/science.1154520

The process of dividing a cell involves generation of various forces - the chromosomes have to be positioned correctly so that they segregate evenly, as well as be pulled towards the daughter cells later on. The membrane also has to contract and separate down the middle to complete the division.

Experiments that investigate these forces are some of the most elegant in molecular biology. A good example is the proof that chromosomes must be under tension via microtubules binding at the kinetochores before they separate - this was shown by taking cells arrested due to one unattached kinetochore, sticking a tiny needle in and 'tugging' the chromosome in the right direction - the cells then undergo mitosis! (http://www.nature.com/nature/journal/v373/n6515/abs/373630a0.html)

This paper isn't in the same league technically, but it's still nice. They add one of the proteins involved in the actual division of the cell to some artificial lipid membrane tubes, and show that it spontaneously forms rings around the tube which contract when given GTP. I wonder how far they can take this system - I think it would be cool if they can get all the way to fission by adding a few more components. As they note at the end of the paper, this is probably how the earliest forms of life looked.

SJP