-48 kb Phage > circularized in st cell aft Linear phage A chromosome in the bacteriophage particle Attachment sites 入 E. coli chromosome gal 入 prophage 菌 a wildtype bacteria Wildtype bacteria Lambda lysogen cell 体 Turbid plaques or Microcolonies of Infect cells with phage ). 与 lawn of bacteria lysogenic bacteria present within turbid plaque 溶 Absence of plaques: no phage A lysis (a) PRm: promoter allowing transcription of cl gene OL: left operator OR: right operator 源 PL: promoter for left genes cl gene PR: promoter for right genes Other Transcription from genes n genes 化 cI mRNA encodes A repressor protein A repressor protein binds to O and OR on any phage lambda chromosome in the cell. This blocks expression of all genes from PL and PR Only cl genes are expressed噬菌体与溶源化