Division in Color

What am I looking at?

This is a video of a single layer of intestinal epithelial cells from an organoid undergoing cell division. These cells are fluorescently labeled for the protein actin. The video is depth-coded for color, which means that cooler colors like blue and purple are closer to the viewer and warmer colors like yellow are farther away from the viewer. Actin is enriched around the cell membrane, which is why you can see each cell’s outline clearly.

Biology in the background

The protein actin is crucial for one of the last steps in cell division – a process called cytokinesis. At the end of cell division, the two resulting cells separate. Actin filaments form a ring in the middle of the parent cell. Then, with the help of a protein called myosin, this ring constricts and separates the membranes of the two daughter cells, completing the process of turning one cell into two. In the video, a short signal burst, corresponding to an increased local concentration of actin, marks the separation of the two daughter cells.

Intestinal organoids vary in shape and size depending on their stage of development and their complexity. They can range from 200 micrometers at their smallest, or roughly 2.5 times larger than the width of a human hair, to 4 millimeters at their largest, or roughly 50 times larger than the width of a human hair.

Technique

This video was created using confocal microscopy.