I don't thing there would be a problem if say pigs organs are manipulated through genetics to be used in human transplant. Anything having to do with a human clone, is I believe strongly condemned.
Actually, I wrote a paper on organ donation a few years ago. You can find the text of that paper on Orthodox Wiki.http://www.orthodoxwiki.org/Organ_donation
I'd have to go back to all my research materials, but I remember that while the Church of Greece has said it has to do more research before establishing a position in reference to xenografts (animal organ donations), other Synods have spoken very strongly against it, as they change or confuse the nature of the recipient.
My other response to the issue would also be that the emphasis that the Church places with regards to organ donation is always on the GIVING of the organ, NOT the receiving (except to say that one should be grateful to God and to the one who donated it). The blessing is in the gift of giving, the sacrifice of love, the ability to help another. It is also clear from the fathers that all healing should be undertaken by both doctor and patient with great prayer and attention not only to body, but to soul as well. Thus, as a pig can not pray, give, love, nor receive a blessing, my response would be that this is crossing the line.
I didn't get into cloning in my paper, but everything I read in the process condemned cloning in no uncertain terms. Interestingly, some of the sources were clear that, should a human clone ever be realized, they would definitely have their own, unique soul.
This is just offhand. I'd have to resurrect from the dead my old computer and try to recover my sources to tell you more. Apologies for the vague nature of my post...
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