Induction of Phage Development in Lysogenic Bacteria

Threlfall

Journal of General Microbiology

et al. 1970

S U M M A R YMutants refractory to colicin E 2, previous phenotypic symbol RefII, have now been divided into two major phenotypic groups. CetC mutants in distinction to CetB mutants show increased sensitivity to U.V. and to a detergent (DOC). CetC mutants may also show other properties, including abortive growth of bacteriophage h and defective division. CetB mutants are refractory to E2 at 30" but largely sensitive at 37". CetC mutants are also refractory at 30" but may be either sensitive or completely refractory at 37". In contrast to Rec-mutants, CetC strains are not sensitive to gamma rays but two mutants show enhanced DNA breakdown after U.V. irradiation. CetC mutants seem defective in a specific membrane component which renders them insensitive to E2 and alteration of which can affect several aspects of DNA metabolism.

Section: Surface Mutants Of E Coli 373mentioning

confidence: 99%

Mutants of Escherichia coli with Altered Surface Properties which are Refractory to Colicin E2, Sensitive to Ultraviolet Light and which can also Show Recombination Deficiency, Abortive Growth of Bacteriophage and Filament Formation

Threlfall

Journal of General Microbiology

et al. 1970

“…From the earliest studies on lambda genetics by Jean Weigle (1953), Francois Jacob and Elie Wollman (1953, 1954) and Dale Kaiser (1955 in volume number 1 of VIROLOGY) in the 1950's until it helped usher in the age of genetic engineering in the late 1970’s and early 1980's, phage lambda was in its golden age at the center of the molecular genetic universe. During those decades lambda was one of the few experimental "organisms" that was sufficiently experimentally accessible to be viewed as potentially completely understandable.…”

Section: Introductionmentioning

confidence: 99%

Bacteriophage lambda: Early pioneer and still relevant

2015

Molecular genetic research on bacteriophage lambda carried out during its golden age from the mid 1950's to mid 1980's was critically important in the attainment of our current understanding of the sophisticated and complex mechanisms by which the expression of genes is controlled, of DNA virus assembly and of the molecular nature of lysogeny. The development of molecular cloning techniques, ironically instigated largely by phage lambda researchers, allowed many phage workers to switch their efforts to other biological systems. Nonetheless, since that time the ongoing study of lambda and its relatives have continued to give important new insights. In this review we give some relevant early history and describe recent developments in understanding the molecular biology of lambda's life cycle.

“…At least two possibilities exist: phage 10 may be a host range mutant of phage 9 or it may originate in a recombination event between phage 9 and elements of phage i during multiplication in R T 10. Jacob and Wollman (10) found that an ultraviolet-irradiated virulent mutant of phage lambda induced prophage in E, coli and also gave rise to various recombinants. The fact that phage 9 did not seem to give rise to variants which form plaques on R T 10 when it multiplied in R T 9 remains unexplained.…”

Section: Discussionmentioning

confidence: 99%

Lysogeny in Rhizobium Trifolii

Takahashi¹,

Quadling²

1961

Can. J. Microbiol.

A pha~e-like particle (phage i ) found in filtrates of Rhirohium trifolii (strain RT 9 ) did not produce plaques h ,~t induced development of two different phages in a pres~~metl c l s i~t i v e Iyso~e~iic strain ( R T 10). These induced phages (phages 9 and 10) differed in their host ranges and prodnccd plaques on strains lil' 9 and R T 10, r~sprctively. Phages 9 and 10 were closel\r related sernlogically anrl were distitlct. from phage i. .\lthou~h ultraviolet irrailiation resulted in the lysis of R T 10, no free pliape was detectable in such Ivsates. Phase i ppwticles h;id morphological, chemical, and physical properties similar to those of functional Rhizobium phages but did not produce plaques on any of 12 R. trifolii strains tested. Development of phage i could be induced with ultraviolet irradiation or by treatment with mitomycin C. from the culture collection of this laboratory. Cultures were preserved in liquid medium Y (5) containing 15% glycerol and stored a t -35' C (18).Active cultures in late Iogarithmic phase were obtained by inoculating 0.2 ml 'Manuscript