-3- 
However, I think that the wording of the proposed definition of "novel" 
DNA molecules could be further improved and simplified. For example, "novel" 
molecules can be defined more simply as "molecules consisting of segments of 
DNA derived from genomes that are not known to replicate within the organism 
used to propagate the recombinant DNA molecule." The situation where two 
species are known to exchange chromosomal DNA is a partial case of this. 
It should be further remembered that two different species which exchange 
chromosomal DNA could contain plasmids or phages that are species-restricted 
and do not integrate with the chromosome of the host species. Accordingly, 
the cloninq of DNA from such elements in a chromosome-exchanqing host 
cannot be strictly considered as "non novel". 
Having arqued in favor of maintaining the proposal to deregulate ex- 
periments not involving "novel" recombinant molecules I wish to point out 
certain corollaries which result directly from this concept and which must, 
in my opinion, be appropriately taken into consideration if the Guidelines 
are to be internally consistent: 
3) Conjugative mobilization of recombinant plasmids from the primary cloning 
host . I would like to propose that the committee consider the possibility 
of allowing the use of conjugative plasmids to mobilize procaryotic recom- 
binant molecules, for example, from HV-1 procaryotic systems. This experiment 
is now prohibited de facto , since HV systems in general are required to be 
free of conjugative plasmids. My reasons are explained in the following 
paragraphs . 
Let's assume that an investigator is interested in identifying and/or 
isolating segments of DNA, from a particular source bacterium A, which 
complement a particular phenotype in certain mutants of that organism. 
[Appendix A — 112] 
