The most astounding fact I picked up in my conversations with Dr Jack Cohen (and then half lost, having no search facilities with me and not even a notebook, so what follows is garbled and unreliable) is that Dolly came from a batch of attempts in which Dr Wilmut tried to insert the telomerase gene into the clones. Amazingly, all those embryos which incorporated telomerase failed; Dolly's genome, however, proved *not* to have taken up the gene.
I was agog at this. Cohen had got it from conversation with Wilmut, I believe, although he said it had been published a few months ago in some relatively obscure place. (I must be making that bit up - how could anything Wilmut has to say about Dolly end up somewhere obscure?)
Anyway, this is all rather startling if correct. Might put a crimp in our plans for Immortality Next Week.
Anyone with better net searching abilities than me should feel encouraged to post more details.