Ever since I’ve been a practicing molecular biologist, we’ve used plasmids as vehicles for genetic engineering. Or, more accurately, we’ve used the entire range of extragenomic information that can replicate inside cells. That would include viral vectors, which have been harnessed for use in both prokaryotic and eukaryotic cells. I sometimes wonder whether this predilection to use episomes has driven perceptions of how synthetic biology should be carried out. If you want to engineer a cell it would seem easiest to add the extragenomic information in a somewhat orthogonal fashion, with its own origin and its own means of being maintained, distinct from the chromosome. I think this is one of the reasons that the “Venter shunt,” synthesizing the whole genome, has attracted so much attention (other than the obvious, of course: that it’s awesome!).
That said, I think that we are beginning to ...
