April 5, 2012

Sometimes I read something that elicits an old-school Joey Lawrence, “Whoa!” I may not be an early 90s heartthrob with voluminous hair, but sometimes the science world makes me sound like one. Today’s image is from a paper on emergence—not a particularly common topic in cell biology, but here the use of microtubules helps to model and test it.

Emergence describes the spontaneous order that can arise out of simple interactions of things. Examples of emergent phenomena in nature include flocks of birds, swarms of bees, ordered crystals of freezing water. The theories behind this collective behavior are tough to test due to the difficulty in controlling all variables and interactions. A recent paper, however, uses emergence at a cellular level to control for all interactions with only a few purified components. Here, Sumino and colleagues used purified microtubules propelled by dynein motors that were bound to a glass surface. Neighboring microtubules, which were on average 15um long, interacted by aligning with each other. Increased density of these local interactions resulted in the self-organization of microtubules into vortices about 400um in diameter, with microtubules rotating and sliding past each other in both clockwise and counter-clockwise directions. Image above shows a lattice formed from many vortices over time (three air bubbles are present with thicker edges).

BONUS! Check out movies from this paper here, under “Supplementary Information.” This one is my favorite!

Sumino, Y., Nagai, K., Shitaka, Y., Tanaka, D., Yoshikawa, K., Chaté, H., & Oiwa, K. (2012). Large-scale vortex lattice emerging from collectively moving microtubules Nature, 483 (7390), 448-452 DOI: 10.1038/nature10874
Adapted by permission from Macmillan Publishers Ltd, copyright ©2012