The effect of multiplicity of infection (m.o.i.) on transcription was studied by infecting Escherichia coli with bacteriophage λcI47, λcI47O29P3 and λcI857cro27P3. DNA-RNA hybridization with γcI47 l-strand DNA, φ80immλ l-strand DNA, and λimm80 l-strand DNA were used to measure mRNA transcription from the l-strand, the l-strand of the early x-P-Q region and the late A-J-b2 region of λ bacteriophage respectively. In λcI47cro+O−P−-infected cells, transcription from the l-strand, l-strand of the early x-P-Q region and the late A-J-b2 region all decreased with increasing m.o.i. The response in the x-P-Q region was less marked than in other regions, but the pattern looked similar to that described above. When phage DNA replication was permitted, as in the case of λcI47, the response was similar to that observed in λcI47cro+O−P−-infected cells, but the level of transcription was increased two- or three-fold. In λcI857cro−P−-infected cells, the leftward transcription and the rightward transcription from the early x-P-Q region and the late A-J-b2 region all increased with increasing m.o.i., but the extent of change was less drastic than with λcro+. This result demonstrated clearly that the decreased in transcription from various regions at increasing m.o.i. of λcro+ was due to the inhibitory action of the cro gene product. The results obtained with cro− strongly support the view that gene dosage is a significant controlling factor for the extent of gene expression.
CohenS. N.,
ChangA. C. Y.1970; Genetic expression in bacteriophage λ. Ⅲ. Inhibition of Escherichia coli nucleic acid and protein synthesis during λ development. Journal of Molecular Biology 49:557–575
EisenH.,
BrachetP.,
Pereira Da SilvaL.,
JacobF.1970; Regulation of repressor expression in λ
. Proceedings of the National Academy of Sciences of the United States of America 66:855–862
FranklinN. C.,
DoveW. F.,
YanofskyC.1965; The linear insertion of a prophage into the chromosome of E.coli shown by deletion mapping. Biochemical and Biophysical Research Communications 18:910–923
KourilskyP.,
BourguignonM. F.,
GrosF.1971; Kinetics of viral transcription after induction of prophage. In The Bacteriophage Lambda pp 647–666 Edited by
HersheyA. D.
New York: Cold Spring Harbor Laboratory;
LukK. C.,
MarkK. K.1980; The phage promoter responsible for the expression of the inserted β-galactosidase gene in bacteriophage λpl ac5. Molecular and General Genetics 178:555–560
McMackenR.,
ManteiN.,
ButlerB.,
JoynerA.,
EcholsH.1970; Effect of mutations on the cⅡ and cⅢ genes of bacteriophage λ on macromolecular synthesis in infected cells. Journal of Molecular Biology 49:639–655
MarkK. K.1970; The relationship between the synthesis of DNA and the synthesis of phage lysozyme in Escherichia coli infected by bacteriophage T4. Virology 42:20–27
MarkK. K.1973; Effect of the N-bypass mutations nin and byp on the rightward transcription in coliphage lambda. Molecular and General Genetics 124:291–304
MeyerB. J.,
MannerR.,
PtashneM.1980; Gene regulation at the right operator (OR) of bacteriophage A. II. OR1, Or2, and OR3: their role in mediating the effect of repressor and cro
. Journal of Molecular Biology 139:163–194
OgawaT.,
TomizawaU.1968; Replication of bacteriophage DNA. I. Replication of DNA of lambda phage defective in early function. Journal of Molecular Biology 38:217–225
RayP. N.,
PearsonM. L.1976; Synthesis of morphogenetic proteins by mutants of bacteriophage lambda carrying tandem genetic duplications. Virology 73:381–388
RobertsJ. W.1975; Transcription termination and late control in phage lambda. Proceedings of the National Academy of Sciences of the United States of America 72:3300–3304
SklarJ.,
YotP.,
WeissmanS.1975; Determination of genes, restriction sites, and DNA sequences surrounding the 6S RNA template of bacteriophage lambda. Proceedings of the National Academy of Sciences of the United States of America 72:1817–1821
TsuiL.,
MarkK. K.1976; The depression of endolysin synthesis in bacteria infected with high multiplicities of phage A. Molecular and General Genetics 143:269–278