The Economist this week has: "Using domestic animals to make human organs".
"Take the fertilised egg of a pig. From each cell in the resulting embryo cut out a gene or genes that promote the development of the animal’s heart. Inject human stem cells from a patient who needs a new heart into the embryo and then place it into the womb of a sow. Wait nine months.I imagine myself recovering from such an operation, munching contentedly on a sausage roll - also sourced from my very own pig.
"The result is an adult pig with a heart made of human cells. The pig can be slaughtered and the heart transplanted into the patient who provided the stem cells, for whom the organ will be a genetic match."
The researchers have already succeeded in mouse-rat organ-sourcing. The human-pig process has not been perfected, however.
"But these are early days. Dr Garry, whose laboratory is now producing two or three pig-human fetuses a week, is studying those fetuses to try to understand why it is that in some only one heart cell in 100,000 is human while in other fetuses the number is one in 100. If he can discover the underlying principle, then the aim of replacing pig cardiac cells entirely with human ones will have come closer."If they can do this for hearts, what about brains? Perhaps they wouldn't bother with that final transplant. Humans get to colonise the entire biosystem .. and the vegans finally win.
We'd obviously have a problem shoe-horning human brains into insects or smaller animals. Probably have to dispense with the sense of humour, that sort of stuff .. .