Donald S. Fredrickson, M.D. 
11/9/77 Pa § e 3 * 
These two organisms, although both closely related members of the genus 
Streptomyces , have not been shown to exchange DNA by natural physiological 
processes, ("although DNA can be exchanged by experimentally induced cell fusion) 
and gene exchange by in vitro methods would come under the NIH Guidelines. 
Since the wild type recipient strain Streptomyces lividans does not have 
"low potential for survival in its natural environment", it could not even 
be classified as an HV1 system. Thus, even though there would probably 
be unanimous agreement by scientists that the experiment I've described 
above poses virtually no risk whatsoever, the experiment could not be 
carried out, even under high levels of physical containment, under the 
proposed Guidelines. 3y defining an HV 1 system in an inappropriate way, 
the authors of the revised Guidelines effectively have included recombinant DNA 
experiments with wild type non-E. coli hosts in the list of "prohibited 
experiments"— Certainly the advisory committee could not have intended 
to place a Streptomyces coelicolor-Streptomyces lividans recombinant DNA 
molecule on the "too dangerous to be done" list, while at the same time 
permitting the cloning of DNA from a wide variety of animal cell and viral 
sources in JE. coli K12 under minimal to moderate containment conditions. 
Yet, this is precisely the inevitable effect of the wording currently 
used. I urgently ask that you resolve this serious inconsistency prior 
to approval of the revised Guidelines. 
I suggest that the problem can be resolved by simply having the 
Guidelines state that "wild type isolets of any bacterial species not known 
to be pathogenic to humans, to domestic animals, or to agriculturally 
important plants may be used as an HV1 host-vector system, provided that 
all components of recombinant DNA molecules introduced into such a host 
vector system, are derived from other prokaryotic organisms within 
Etiologic Agent Class 1. Use of a non-E. coli HV system for the propagation 
of genes derived from organisms other than those included in Etiologic 
Agent Class 1, or which are derived from eukaryotic organisms, shall be 
subject to certification as described in the Guidelines." 
I believe this modification will provide adequate safety while still 
enabling work of great importance and minimal hazard to proceed. 
(3) L evels of biological and physical containment for certain 
experiments . In most instances, the investigator is given the option of 
using either P2 + EK2 containment or P3 + EK1. However, in the se'ction 
dealing with shotgun experiments from mammals other than primates (page 
49601 of the Federal Register, September 27, 1977), and in the experiments 
dealing with DNA from birds, there is. no option of trading a higher level 
of physical containment for a lower level of biological containment. 
Depending on the gene to be cloned, there may be legitimate and compelling 
experimental reasons for an investigator to wish to use P3 + EK1 for 
such experiments, rather than P2 + EK2. For example, the approved EK2 
host (or hosts) may not be suitable for detection of the gene to be 
cloned (e.g. the thy A mutation of X1776 prevents detection of expression 
of mammalian genes coding for the enzyme dinydrof olate reductase, since the 
host bacterial strain is already resistant to trimethoprim and methotrexate). 
[Appendix A — 314] 
