But not only do the stem cells morph, so do the sugars on their surface. The sugars are chemically and biologically different on a stem than on an adult cell. It's not clear why that should be the case, but it may turn out to be very helpful a few years, or possibly decades, down the road.
It may help, for example, locate stem cells in a mature organism and reprogram them to fix a broken spinal cord.
"We now know that early embryos have mostly stem cells," Bertozzi said. "But even adults, you and I, still have a few stem cells in our bodies and we rely on those stem cells to help regenerate damaged tissues and damaged cells. If we could just harvest our own stem cells and use them to regenerate organs, we would have an incredible opportunity to treat degenerative diseases, many of which are associated with aging.
"But adult stem cells are hard to find and hard to isolate because they are few and far between," she said.
It may be, however, that those adult stem cells have a unique signature in their sugar coating, and thus they may not be as hard to find, and as hard to reprogram, as it seems.
Bertozzi's colleagues published their findings in the Proceedings of the National Academy of Science. The lead author is Jeremy Baskin, who is now doing post-doctoral research at Yale University.
The researchers are excited about their work because it adds to our understanding of how nature works.
"Obviously, that's a major driving force," Bertozzi said.
But if they can figure out this complex puzzle, the possible list of applications is endless.
For example, some scientists contend that despite the wonderful role stem cells provide in creating the organs and tissues that make life possible, there may be a few bad apples in the crowd. Some believe some stem cells actually cause cancer, or at least allow it to spread, but that's a very contentious arena.
If it's true, and if the code in the sugar coating can be deciphered, it may be possible to target those cancer-causing stem cells and wipe them out before they do all that damage. But that's a long shot. No one really knows at this point.
But if Bertozzi's team is right, there is no doubt that sugars are major players in changing a clump of cells into a distinct living organism. And a small fish is allowing them to do "transformative research" because it is, well, so transparent.
"Zebra fish are a far distance from human beings, on the one hand," she said. "But on the other hand, they are vertebrates and when you get right down to it we share a lot of the same bits and pieces. Our parts list is not too different from theirs."