Construction and physical map of a Bacillus subtilis specialized transducing phage .RHO.11 containing B. subtilis lys+ gene.

Abstract
The lys+ gene was detected as the smallest DNA. fragment (2.5×106 dalton) among the several genetic markers tested from EcoRI-cleaved B. subtilis chromosomal DNA preparations by agarose gel electrophoresis followed by identification with DNA mediated transformation experiments. The DNA fragment retaining the lys+ gene was cloned in a B. subtilis temperate phage ρ11 using the prophage transformation method. The molecular weight of the genome of the constructed specialized transducing phage (ρ11dlys+) was estimated to be 72-73×106. The phage was cross-reacted with an antiserum against ρ11 phage particles. The physical map of ρ11dlys+ DNA using SalI and BamHI was quite different from that of ρ11 DNA. ρ11dlys+ did not carry theρ11-coded thymidyrate synthetase gene.