20 
they request permission to remove such clones frcm the original 
containment conditions and to perform subsequent work with them 
under PI + EKl conditions. 
(3) If they can identify nontoxinogenic fragments of the structural 
gene(s) for Shiga-like toxin, the investigators request permission 
to: 
(a) Remove any such cloned nontoxic fragments (generated 
during the search for clones that contain intact toxin 
structural genes) frcm the original containment conditions 
to work with them under PI + EKl conditions; and 
(b) Directly clone any such nontoxic fragments into ooli K-12 
under PI + EKl conditions. 
(4) If the structural gene for Shiga-like toxin is shown to be present 
in a specific bacteriophage genome and its physical location is 
determined, then they request permission to: 
(a) Remove from the original containment conditions any clones of 
fragments of phage gencme (generated during the process of 
obtaining cloned toxin structural genes) that do not correspond 
to toxin structural genes and to work with them under PI + EKl 
conditions; and 
(b) Directly clone any fragments of the phage gencme that do not 
correspond to toxin structural genes into coli K-12 under 
PI + EKl conditions. 
(5) If in future experiments the investigator can isolate nontoxino- 
genic alleles of the structural gene(s) for Shiga-like toxin by 
transposon mediated mutagenesis (insertions! inactivation) or by 
chemical mutagenesis, they request permission to clone these 
nontoxinogenic alleles of the toxin structural gene(s) into Jk_ coli 
K-12 under Pi + EKl conditions. 
Dr. O'Brien and coworkers supplied additional data in support of these 
requests . 
Dr. Gottesman said that at the February 6, 1984, RAC meeting, she had voted 
against the motion to lower containment frcm P4 to P2 because she felt 
certain questions had not been fully addressed. Her perception of the 
sentiment of the carrmittee at that meeting, however, was that RAC overwhelm- 
ingly favored the motion in spite of the split vote. She felt the split 
vote partially reflected a disagreement over whether the motion should 
provide an exclusive approval for Dr. O'Brien's group. 
Dr. Gottesman said subsequent to the February 6 RAC meeting, Dr. O'Brien 
had submitted a revised proposal on April 4 and that NIH had convened the 
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