APPENDIX A 
Statement on the use of Bacillus subtilis in recombinant molecule technology 
Unquestionably, Escherichia coli is the most well characterized uni- 
cellular organism. Years of basic research have enabled investigators to 
develop a well characterized genetic map, to obtain detailed knowledge of 
virulent and temperate bacteriophages, and to explore the physiology, 
genetics, and regulation of plasmids. More recently, the development of 
DNA-mediated transformation has permitted exogenous fragments or molecules 
of DNA to be incorporated into the genome or to reside as self-replicating 
units. The discovery of transformation of Bacillus subtilis by Spizizen (1) 
stimulated the development of an alternative model system. The purpose of 
this report is to summarize the current status of this genetic system and 
to describe the actual and potential vectors and vehicles available for 
recombinant molecule technology. 
A. Current knowledge of the chomosomal architecture and mechanisms 
of genetic exchange in B. subtilis 
Two mechanisms of genetic exchange have been utilized to establish 
the linkage map of B_. subtilis , DNA-mediated transformation (capable of 
transferring approximately 1 % of the genome) and transduction with 
bacteriophage PBS1 (capable of transferring 5-8% of the chromosome). 
Recent detailed genetic studies with PBS1 by Lepesant-Kejzlorova et a]_. (2) 
have resulted in the development of a circular genetic map for this organism. 
The current edition of the map (3) contains 196 loci. Biophysical analyses 
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