But I think one has to be realistic and say the kind of technology we have would work if applied to humans. This protein contains just about all the amino acids a newborn human needs. The Roslin cloning served as a next step to replicat such transgenic animals. Generally adult somatic cells have already specialized to the point where they will not transcribe all the genes necessary to develop a differentiated embryo. As a result skin cells do not make estrogen, brain cells do not make insulin.
Proteins seem to block a cell's access tothese genes.
They grew the cells in lab dishes imersing them in nutrients. Then in the eureka step they dialed back the nutrients to a twentieth of what the cells need to grow. After five days the cells had become quiescent, stilled at exactly the stage in the life cycle where their genes are open to 'reprogramming of gene expression' and thus able to be reactivated by cytoplasmic signals from the ovum into which they are implanted. Of 227 adult cells fused with ova, only 13 pregnancies resulted and only one - Dolly was born alive. The experiment at Roslin has also been repeated in New Zealand.