- 2 - 
I would urge you to permit the use of baker's yeast as a host for recombinant 
DNA. In making this request I am not asking for exceptions to the N.I.H. Guide- 
lines. In fact, to permit the use of yeast as a host would be fully consistent 
with these guidelines which urge: "Thus, while proceeding cautiously with E. coli , 
serious efforts should be made toward developing alternate host -vector systems; 
Yeast is an ideal alternate host system. On pg. 27920, under (c) at the top, 
the level of containment for fungal or similar lower eucaryotic host-vector 
systems is given. "We therefore consider that the containment guidelines given 
for experiments with E^ coli K12 and other procaryotic host-vectors (Section III 
B-l and -2 respectively) provide adequate direction for experiments with those 
lower eucaryotic host-vectors". In effect, allowing the use of yeast as a host 
would be a more liberal interpretation of a portion of the guidelines which is 
somewhat ambiguous. This more liberal interpretation would remove the inequalities 
of the current situation and permit the development of a safer cloning host. I 
believe that such an action would restore confidence in the N.I.H. and its ability 
to oversee the development of recombinant DNA technology in our country. 
Sincerely 
GRF : fo 
Gerald R. Fink 
Professor of Genetics 
[Appendix A — 237] 
