Original Repository: Stanford University Libraries. Department of Special Collections and University Archives. Paul Berg Papers
Reproduced with permission of Paul Berg.
Medical Subject Headings (MeSH):
Recombinant DNA Technologies and Researchers' Responsibilities, 1973-1980
Dear Dr. Gartland,
I have been searching the revised Guidelines and the proposed amendments to be reviewed at the February 15-16 meeting of RAC
for a clear statement concerning the introduction of recombinant DNAs into whole animals.
As you know the experimental ground work for such experiments has already been provided by Dr. Beatrice Mintz's experiments.
She has shown that teratocarcinomacells grown in culture can be incorporated into mouse blastocysts which ultimately can yield
mice containing a variety of cell types derived from the teratocarcinoma cells. Using appropriate selections it is feasible
to introduce exogenous DNAs (be they derived by recombinant techniques or otherwise) into such teratocarcinoma cells and hence
Inasmuch as many cloned mammalian genes will be coming available for such experiments it is important to develop a policy
for performing such experiments. In my view I can not see any justification for hesitating to insert recombinant DNAs into
animals via this protocol, particularly since rabbit, chicken, human etc. DNA segments can be injected directly into blastocysts
without any restrictions or regulations. DNA approach is more sophisticated and controlled since it permits the use of selected
genes and, therefore permits the production of donors e.g., genetically modified teratocarcinoma cells. This greatly simplifies
the process of identifying the cells that carry the newly introduced genes.
It seems wise to me for RAC to anticipate this line of research and to formulate interim and longer-term policies about this
research. I hope this can be done expeditiously and if needed I would be glad to testify to the tremendous scientific and
medical importance of such experiments; however, there are others (Bea Mintz, in particular) who could do it far more ably.