The biological process that results in a human being starts with a single fertilized egg, and it fascinates stem cell researcher Janet Rossant. She’s spent many years researching the fundamental question of how that transformation happens, as that one cell divides into many cells that specialize to make all the tissues of the human body.
Rossant is the President & Scientific Director of the Gairdner Foundation and Chief of Research Emeritus at SickKids Hospital in Toronto. Her research starts from the very first cell division that an embryo undertakes.
“One of the first things they do is make cells that make placenta and cells that make the embryo,” says Rossant. “The cells that make the embryo are what we call pluripotent cells, and they are the cells from which you can get pluripotent stem cells.”
These cells could be the foundation of stem cell treatments for degenerative diseases because they have the ability to make any specialized cell type in the body.
“Along the way we’ve gone off into other things and studied brain development, heart development, blood vessels,” adds Rossant. “We keep coming back to that tiny little embryo, and that’s what we’re still doing today.”
Embryonic development is such a rich process that there is still so much to learn. Rossant and her team use genetic manipulation, live imaging, proteomics, and single cell expression analysis to explore how cells specialize during development.
After growing mouse embryonic stem cells in a petri dish in the lab, Rossant wondered whether she could still make a complete mouse out of them.
And so she did just that.
“We did a little genetic trickery,” explains Rossant. “We gave those stem cells other cells that could make the placenta, and then we had little mice running around that were perfectly normal and had been derived from cells that had been grown for many generations in a petri dish.”
The experiment is incredible proof that even after being grown in a lab, pluripotent stem cells can still make any cell type that is needed for treatment. Researchers just need to figure out how to nudge them to become the cells they need. And that’s an exciting insight for regenerative medicine.