May 21-23 - MINUTES OF MEETING 
6 
IV. MINUTES OF FEBRUARY 15-16, 1979 MEETING 
The RAC reviewed the Minutes of the February 15-16, 1979 meeting. 
Dr. Krimsky suggested that a verbatim transcript of Dr. Fredrickson's 
renarks should be included in the Minutes. Dr. Walters suggested that 
two other items be included in the Minutes. With these changes, the 
RAC approved the Minutes by a vote of 19 to 0. 
V. USE OF AGROBACTERIUM TUMEFACIENS AS A HOST-VECTOR SYSTEM 
A. Request from Dr. Mary- Dell Chilton 
Dr. Mary-Dell Chilton of the University of Washington submitted 
a proposal (654) for approval of Agrobacterium tumefaciens and 
its Ti (tumor- inducing) plasmid as a host-vector system for 
recombinant CNA experiments. Crown gall tumors caused by A. 
tumetaciens , a uoiquitous inhabitant of the soil, are induced by 
tumor genes located on the large Ti plasmids. The Ti plasmid 
enters plant cells and inserts itself in the plant chromosomal 
ENA. The Ti plasmids appear promising as vectors for introduction 
of aesireu foreign DNA into higher plants. 
Notice of this proposal was first published in the Federal 
Register , April 13, 1979 as follows: 
"Non-disabled strains of Agrobacterium tumefaciens 
can be used in combinations with the cointegrate 
plasmid Ti::RP4 as a host-vector system at the P3 
level of physical containment." 
No comments were received by the Office of Recombinant CNA 
Activities during the 30-day period following the publication 
of this proposal. On April 25, 1979, Dr. Chilton submitted 
a supplement (674) to her original proposal which represented 
an alternative approach for using the Agrobacterium system 
that would provide greater biological containment. The new 
strategy was described by Dr. Chilton at the RAC meeting on 
May 21, 1979. First, eukaryotic DNA would be inserted in a 
no'rt-conjugative plasmid, i.e., pBR322, that also contains frag- 
ments of Ti plasmid DNA and an insert of the origin of 
replication of other cryptic Agrobacterium plasmids. The 
plasmid would be propagated in L. coll K-12 and the recombinant 
DNA molecules used to transform A. tumefaciens . The A. 
tumefaciens host strain would then be employed to induce 
tumors m higher plants. The advantage of the newer strategy 
is that it avoids the involvement of RP4 which is a wide 
range conjugative replicon. Dr Chilton proposed a one- step 
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