Bacillus subtilis bacteriophage SPβc1 is a deletion mutant of SPβ

Abstract
The restriction fragment patterns of two mutant forms of the temperate Bacillus subtilis bacteriophage SPβ have been examined. The DNA of a heat-inducible mutant, SPβc2, which has a molecular size of 128 kilobases (kb), yields the same restriction pattern as the wild type SPβc+ DNA. The DNA of a clear-plaque mutant, SPβc1, has a molecular size of 117 kb, and is deleted for an 11 kb region of phage DNA. Neither SPβc1 nor SPβc2 DNA is cleaved by the endonuclease HaeIII.