162 
MR. HUTT: Well, I understand. 
DR. GOLDSTEIN: Other than that, I sort of accept your position. There 
is an EK2, and I was really pleased to hear that. I hope more work goes 
into that. 
MR. HUTT: But you are not suggesting, in short, that there should be 
a moratorium until something other than IS. coli is available? 
DR. GOLDSTEIN: Well, I think some kind of a limit should be put on 
in the sense that — 
MR. HUTT: Could you be more specific? I am having trouble 
understanding. 
DR. GOLDSTEIN: In the original set of guidelines which we sent to the 
committee before the La Jolla meeting, we suggested two years be given with 
EL coli . 
MR. HUTT: Two years? 
DR. FREDRICKSON: Dr. Singer? 
DR. SINGER: I want to make a comment about the question of alterna- 
tives to IS. coli , because I think that at this point it is not clear to me 
anyway that there will ever be an alternative which in fact offers any 
advantage, and the reasons are the following. 
We know now that IS. coli K12 does not colonize normal human bowels. 
Now, what we said we would look for in an alternative system is something 
which has a peculiar ecological nature which doesn't include the coloniza- 
tion of humans. The more serious problem is the exchange of genetic 
information from IS. coli K12 to certain other organisms, other kinds of EL 
coli in other organisms. We know a fair amount about the kinds of organisms 
which will accept DNA from IS. coli K12. 
One of the things that we are going to have to learn about any possible 
alternative organism is whether it can exchange genetic information with a 
whole series of common and not so common organisms. At this point we don't 
know anything about alternative organisms in these terms, and it seems to me 
that if it is not clear before we start that we will in fact find an organ- 
ism which is unable to exchange readily with a lot of other cloning organ- 
isms, and until we know that, then it is not clear that we will ever have an 
organism that is better than EL coli K12. So while I am certainly not 
saying that I don't think we ought to be looking for such a thing, I don't 
think we can go on the assumption that there will one day be something that 
is better. 
[303] 
