Re: [DIYbio] Curious about zink finger nuclesases / gene therapy

Speaking as someone who used to do genome editing -

ZFNs were always simply too hard to evolve/select into a working
reagent for targeting a new DNA string.  Only dedicated labs were
working on them, and even then progress was slow.  TALEs already seem
to be easy enough for a determined individual in a lab to build a new
reagent with.  Plus, there has only been minimal work optimizing this
new family.

Although size is an issue in AAV viral vectors, not being to get a
protein that targets your string of choice is a much bigger issue!
There just aren't that many sites you can target with ZFNs.

Besides, one of the major application of these proteins is editing the
germline (via NHEJ deletions or HR swaps), in which case the size of
the genetic payload doesn't matter much (since microinjection is often
used here).  The first successful demonstration ever of targeted HR
editing of the zebrafish happened very recently using TALENs.

-a