[alex-g]

I don't know a lot about biology, but I do know a lot about proofs, provenance, zero-knowledge, etc. I wonder if there is some way, in an experiment of this kind, to tell whether the embryonic stem cells obtained are "really" derived from an adult mouse, as opposed to being extracted from an ordinary mouse embryo. In that case, third parties could verify the claim just by looking at the cell cultures. But I assume that they are actually completely normal-looking, as this is the point of the protocol.

Otherwise, perhaps it is possible for the provenance to be deliberately marked in some way that is resistant to forgery. For example, the adult cells used could be provided by some independent source who is generally trusted not to "leak" the corresponding embryonic cells. Then, if you produce ESCs with the right genome (which is easy to test), you must have done it using adult cells alone. If a clever and unscrupulous biologist could forge that - say by taking a normal ESC and injecting foreign genetic material, or by cloning the mouse and harvesting the new embryo - then perhaps some alternative marker could be devised. It would have to be something that could be introduced into the adult mouse cells, but couldn't be easily extracted, swamped by a new marker, or transferred in the cloning process. Or we could cross-check against other signs that those methods might have been used - some biological equivalent of tamper-evidence, maybe?