So there is a sheep in Nevada that is 15% human due to the injection of human fetal stem cells. Cite and more cites. Supposedly (or perhaps the better term is hopefully) the animal will have organs and marrow that are interchangable with those of humans.
Here’s where my scientific illiteracy comes out to embarass me: What would be the effect of the human stem cells on the lamb organs that would allow it to be transplanted (for it’s still 85% lamb)? Wouldn’t a primate seem a better choice to experiment on? If this lamb grows up and is fertile, and if it mates with other sheep who’ve had this “procedure”, will their offspring have human cells?
And since it’s never been more appropriate to make an awful pun,
I’m just hoping they’ll keep going til they make a real race of centaurs. It’ll answer questions I’ve always had, like whether when they’re newborn they run around like a newborn colt or just kinda lay there like a human newborn or, worst case scenario, the horse part runs around while the human part just droops.
Sheep are probably used (instead of a primate host) since they mature faster and have reasonably human-sized organs. To get a large organ from a primate, you’d be looking at using chimps, and the process would take too long. There might be other ethical reasons for not using chimps in this type of research (if we ignore the ethical problems of the chimera-producing procedure in the first place).
If I understand the procedure correctly, the human stem cells are injected into the peritoneum of the sheep fetus, so it would be fairly well developed at that point and the stem cells wouldn’t migrate into the sex organs, and so they wouldn’t be passed on to future generations thru the gametes produced by those organs. It also sounds like the organs would be more than 15% human even if the sheep had only 15% human cells total. Presumably, certain organs would contain mostly human cells and the rest of the sheep would be composed entirely of sheep cells.
This is, of course, a question that one can reasonably expect to one day actually be answered in court. The companies developing these technologies will have a serious financial stake in having it go their way. The dictionary defines human as a member of H. sapiens. So it could come down to defining what species an interspecies hybrid “really” is and that usually comes down to reproduction. When you have a sheep that can give birth to a human (a reasonable prospect for the future), you’ll really have a legal mess.
I used to work in a place that made artificial heart valves for humans from heart valves harvested from pig hearts. Thousands of medical products coming from animals are used every day to save millions of human lives. To someone faced with the choice of getting a liver grown in a sheep or death, it probably wouldn’t seem so icky. Especially since it is likely that their genetic material will be used to grow the liver they need. Sign me up; I’ll take the sheep deal over death any time.
Nitpick; it’s a chimera, not a hybrid. A hybrid is a genetic combination, like a mule. A chimera is a mix of two or more genetically seperate ( in this case two species ) groups of cells; the genes don’t mix.
Uncertain, but hopefully not too bad for the animal. I don’t think that they intend to try a transplant with a mere 15%, however.
Yes and no. Obviously they’d be more compatible. However, sheep as pointed out breed faster, and primates large enough to hold human organs tend to be hard to handle, smart enough to be ethically problematic to cut up for organs, more prone to human-compatible diseases, and rare/endangered.
Probably not more that a few stray cells - or in theory, human with only a few stray sheep cells ( not that the latter would survive, I bet ). It would depend on if they chimericized( sp ) the animals ovaries/testes with human cells, for some reason. There’s no genetic merging; if they are just trying to grow a human liver in the sheep, it’ll just have sheep as offspring.