Thanks to the MIT Technology Review, I've learned that it is technically not impossible for a blood cell to turn into an egg cell, thanks to a process called in vitro gametogenesis:
The first step is to take a cell from adult—say, a white blood cell—and convert it into a powerful stem cell. That process relies on a Nobel Prize–winning discovery, called reprogramming, that allows scientists to induce any cell to become "pluripotent"—capable of forming any other type of tissue. The next step: cajole those induced stem cells to become eggs whose genetic makeup would match that of the patient.
It's the last part that's the scientific challenge. Certain cell types are very easy to make in the lab: leave pluripotent stem cells in a dish for a few days, and some will spontaneously start to beat like heart muscle. Others will become fat cells. But an egg might be the hardest cell to produce. It's huge—one of the largest cells in the body. And its biology is unique, too. A woman is born with her full complement of eggs and never makes any more.
Researchers in Japan have apparently succeeded in converting skin cells into fertile eggs. As the Tech Review also explained:
Starting with cells from a tail clipping, they'd induced these into stem cells, which they then directed partway along the path to becoming eggs. Then, to finish the task, they incubated these proto-eggs alongside tissue collected from ovaries of mouse fetuses. In effect, they had to construct mini ovaries.
This is some wild science. And the rest of the article is equally fascinating, focusing on a Silicon Valley startup called Conception that's trying to replicate this process for humans. While they haven't been successful yet, the potential for the technology is pretty astounding. The most obvious application is to allow people with ovaries to conceive even after their egg supply has naturally diminished. But it also means that a single person could theoretically fertilize an egg made from their own blood. Or four people could lend their DNA to a single embryo. And of course, this all could eventually lead to wild implications for designer children.
What a time to be alive.
How Silicon Valley hatched a plan to turn blood into human eggs [Antonio Regalado / Technology Review]
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