THE UNIVERSITY OF NEBRASKA-LINCOLN 
LINCOLN, NEBRASKA )fc)&6X>)& 68583 
January 3, 1978 
Reply to: 
Department of Plant Pathology 
304 Plant Industry Building 
East Campus 
(402) 472-2858 
Dr. Donald S. Fredrickson, Director 
National Institutes of Health 
Department of Health, Education & Welfare 
9000 Rockville Pike 
Bethesda, Maryland 20014 
Dear Dr. Fredrickson: 
This letter is in elaboration of my comments at the Dec. 15-16 
meeting of the Advisory Committee to the Director, NIH. 
1. The proposed revision on Recombinant DNA Research still 
retains the phrase "The capacity to infect some host cell" 
(p.49596) in the definition of recombinant DNA molecules. 
The term "infect" is not normally applied to agents, such 
as plasmids, requiring the specialized treatment used in 
recombinant DNA experiments for entry into host cells. 
The term is apt to be misleading to the public who may 
equate recombinant DNA molecules with pathogens which infect, 
(i.e. invade) and cause disease in their host. I therefore 
support the substitute definition proposed by Paul Berg 
(letter of December 5, 1977, document 31) in which recombinant 
DNA molecules are defined as "molecules which have been con- 
structed outside of living cells by joining natural or 
synthetic DNA segments to DNA molecules that can replicate 
[in] or be integrated into the genome of a living cell". 
2. Affirming the testimony of Dr. Chilton, and the letters of Drs. 
Day (document 28) and Kado ert al. (Dec. 5, 1977), I support 
deletion of the words "and plant pathogens" (p. 49602). P2 + 
EK2 or P3 + EK1 conditions are sufficient for most allowable 
plant pathogens. In fact, PI + EK2 or P2 4- EK1 conditions are 
undoubtedly sufficient for most allowable experiments. 
As indicated by many investigators, the crown gall bacterium 
Agrobacterium tumef aciens offers the most promise for introducing 
foreign DNA into plants. Yet there is concern (Albersheim, 
document 1; Simring, Dec. 15 remarks) that this bacterium poses 
hazard to agriculture. It would be ironic to further restrict, 
by P3 - EK2 conditions, for example, experiments with A. tumefaciens 
since work on the genetics of this bacterium and its plasmids is 
progressing more rapidly than for any other bacterial plant patho- 
gen. This work includes analysis of the genes determining patho- 
genicity. The possibility thus exists for excision of pathogenicity 
determinants without loss of those determinants for entry 
THE UNIVERSITY OF NEBRASKA-LINCOLN [Appendix A 175] THE UNIVERSITY OF NEBRASKA AT OMAHA 
THE UNIVERSITY OF NEBRASKA MEDICAL CENTER 
Institute ot Agriculture 
and Natural Resources 
