"Unmodified transposons (wild-type) that become 
inserted into a genome, even if carried by a 
recombinant vector or plasmid, are not subject to these 
Guidelines. For example, it is common to use vectors 
that either are naturally unstable (suicide vectors) in 
a desired host or that can be rendered unstable by- 
manipulating physiological conditions. In the process 
of suicide (inability of the vector to replicate), 
transposon transfer may occur. This process is not 
considered recombinant DNA." 
Dr. Vidaver said the amendment was proposed because of a 
definitional problem of what constitutes recombinant DNA. She 
said this had come into question in the case of a suspected 
violation of the NIH Guidelines by an investigator who released a 
bacterium into the environment that had enhanced fungicidal 
activity generated by transposon mutagenesis via a recombinant 
plasmid vector. However, the recipient bacterium contained only 
the unmodified transposon from the vector. 
Dr. Vidaver said two comments had been received that offered 
amendments to wording of the proposed amendment. The first, from 
Dr. John Payne of USDA’s Animal and Plant Health Inspection 
Service, proposed adding the following language to the end of the 
first sentence of the proposed amendment: 
"...if the recombinant vector or plasmid are no longer 
present in the cell." 
Dr. Vidaver said this would be accepted by her as a "friendly 
amendment," if it were so moved, with the exception that she 
would rather replace the word "if" at the beginning of the 
suggested amendment with the words "provided that." 
Dr. Vidaver said tab 1342 was a letter from Dr. Jack J. Manis of 
the Upjohn Company who proposed adding the following paragraph to 
the proposed amendment: 
"Likewise, strains resulting from the deletion of a 
recombinant transposon or exchange of a recombinant 
transposon for a wild type transposon via site-specific 
or homologous recombination are not considered to be 
recombinant and are not covered by these Guidelines." 
Dr. Vidaver said she favored the addition presented by Dr. Manis. 
however. Dr. Vidaver did not want her original proposal to be 
impeded by the wording of this addition and said she preferred 
this to be a separate issue from the original proposal. 
Dr. Riley supported the proposal including the modification by 
Dr. Payne. However, Dr. Riley said she could not agree with the 
[258] 
Recombinant DNA Research, Volume 13 
