See the fireworks--under a microscope

The night sky will be aglow with fireworks this 4^th of July. But here’s a video of some “fireworks” that take place without the rockets’ red glare or the bombs bursting in air. In fact, this pyrotechnic display occurs under a microscope.

This video shows how microtubules—the hollow filaments that serve as the skeleton of the cell—dynamically assemble during cell division. While that descripton alone may not elicit "ooh's" and "ahh's," rest assured that the video does depict something quite exciting and brand new.

Microtubules were believed to grow linearly, but researchers knew they also had to somehow branch out to form the bipolar spindle structure. But no one had been able to visualize this process in animal cells to understand how the microtubules start out in a straight line but wind up spreading out.

In this video, Sabine Petry, PhD, and colleagues in the Department of Molecular Biology at Princeton University, in Princeton, NJ, captured for the first time how microtubules branch out, like the burst of a firework, during cell division. The video shows how new microtubules (red with growing tips in green) grow off the wall of existing microtubules.

“Microtubule branching amplifies the microtubules while preserving their polarity and explains how microtubules can cause the mitotic spindle of a dividing cell to reliably segregate chromosomes,” the researchers concluded in their 2013 study in the journal Cell.

Also worthy of note: this clip claimed 1st place in the video category of Princeton University’s 2014 Art of Science competition.