I mean think about it. One day, an animal is just a fertilized egg. Then it divides into two cells, both with the same DNA, and you’d think with all the same cellular juices from that original egg. And those divide. And those divide. And somewhere along the way, one of those cells up and becomes different. And the cells around it become different. And before you know it the cells are organized into a front and back, left and right, and specialized cells like skin, neurons, and muscle. How crazy is that?
The question isn’t just navel-gazing. Answering it could also help us treat diseases that occur when the cells don’t quite get around to being different.
For my tastes, the question was more interesting than the lab work, which is why I turned to writing. But thankfully there are others still at it, including our grantee Roel Nusse at Stanford University. He turned his (and his lab’s) attention to understanding how a single embryonic stem cell in a lab dish divides and eventually produces cells that are different from itself. This is a critical step for all those researchers who are working to grow stem cells into different cell types for use in treating or studying disease.
A press release from Stanford quotes Nusse talking about his work, which was just published in Science:
“In the body, it is likely that every cell grows and differentiates in some kind of orientation,” said Roeland Nusse, PhD, professor of developmental biology. “Without this guidance, specialized cells would end up in the wrong place. Now, we can study the division of single mammalian cells in real time and see them dividing and differentiating in an oriented way."Stanford’s release includes a nice description of exactly how Nusse and his team carried out the painstaking work. It involved coating tiny beads with a protein that’s known to prod stem cells to divide, then attaching the bead to a specific spot on the cell. They could then watch, in real time, how the cell divided in relation to the bead.
It’s meticulous work, and will likely be important for future stem cell therapies. But it makes me glad I wasn’t the one carefully placing that bead on the cell, or sitting there watching it divide (paint dries about as quickly).
CIRM funding: Roel Nusse (RB4-05825, TR1-01249)
Habib, S., Chen, B., Tsai, F., Anastassiadis, K., Meyer, T., Betzig, E., & Nusse, R. (2013). A Localized Wnt Signal Orients Asymmetric Stem Cell Division in Vitro Science, 339 (6126), 1445-1448 DOI: 10.1126/science.1231077