addition of the language presented by Dr. Manis in his letter 
because of conditions contained in the language which have been 
previously considered and still remain unresolved. 
Dr. Erickson said he would have no trouble with the proposed 
amendment if it were applied only to plants and bacteria; 
however, he noted that mammalian biologists could consider 
retroviruses as transposons and said he would not like to have 
experiments with retroviruses be excluded from the NIH 
Guidelines . 
Dr. Vidaver asked if such experiments would meet criteria for 
being recombinant DNA. Dr. Erickson said cells could be infected 
by a retrovirus carried in a new plasmid or vector and cause a 
burst of mutagenesis or activation of intrinsic retroviruses and 
be excluded from review under the NIH Guidelines if this proposed 
amendment was in place. 
Dr. Roberts said that stipulating the plasmid has to be out of 
the cell is not necessary since that is already defined as 
recombinant DNA. What should be of concern is the definition of 
"recombinant DNA" as opposed to the fate of the cells in which an 
experiment is performed. He added he did not believe 
retroviruses were technically transposons and did not think 
anyone would try to interpret them as such. 
Dr. Gellert supported Dr. Erickson and mentioned the discussions 
of the RAC relative to transgenic animals where much the same 
issues were discussed relative to the introduction of "stable 
recombinant DNA, or DNA derived therefrom." Dr. Gellert said 
this was a case where it was possible to insert "DNA derived 
therefrom" without its being literally recombinant and thus be 
excluded from review under the NIH Guidelines. 
Dr. Elizabeth Milewski of the Environmental Protection Agency 
(EPA) asked Mr. Lanman for his opinion on how changes in 
definitional language would affect interagency coordination of 
efforts. Mr. Lanman said he believed all agencies involved 
should be working with the same definitions and asked 
Dr. Milewski whether EPA had developed a definition for 
recombinant DNA. She replied EPA was operating under a policy 
statement. Their language defining recombinant DNA was DNA that 
was "intergeneric," coming from organisms classified in different 
genera, in order to fall under EPA regulation. She said she was 
not familiar enough with biological issues of transposons to know 
if that would have an impact on the EPA definition. 
Dr. Davis said he was surprised that a virus could be called a 
transposon. Dr. Erickson said in many instances journal articles 
have referred to retroviruses as "mammalian transposons." He 
suggested clarifying language be added to the proposed amendment 
Recombinant DNA Research, Voiume 13 
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