High mol. wt. DNA was extracted from Escherichia coli lambda lysogens and was shown to be infectious. Its infectivity was due to prophage DNA integrated into the host chromosome rather than to DNA released from mature phage particles, as established by the following criteria: the titre of infectious DNA exceeded by 100-fold the titre of infectious units present before DNA extraction; mild shear selectively reduced prophage DNA infectivity to 2% of the unsheared DNA while lambda phage DNA infectivity retained 50% of its infectivity; DNA extracted from an E. coli (lambda c857 tsxisam6) lysogen yielded 200 times as many plaques on sup+ than on sup− spheroplasts. Thus lambda prophage DNA infectivity depends on expression of the excision gene while the infectivity of non-integrated forms of lambda does not. About 104 genome equivalents of E. coli DNA yielded one infectious centre unit in this assay system; this high infectivity should make prophage DNA a useful marker in genetic transformation experiments.
ArmentroutR. W.,
RutbergL.1970; Mapping of prophage and mature deoxyribonucleic acid from temperate Bacillus bacteriophage 1/H05 by marker rescue. Journal of Virology 6:760–767
ArmentroutR. W.,
RutbergL.1971; Heat induction of prophage ^105 in Bacillus subtilis: replication of the bacterial and bacteriophage genomes. Journal of Virology 8:455–468
BolingM. E.,
SetlowJ. K.,
AllisonD. P.1972; Bacteriophage of Haemophilus influenzae. I. Differences between infection by whole phage, extracted phage DNA and prophage DNA extracted from lysogenic cells. Journal of Molecular Biology 63:335–348
CosloyS. D.,
OishiM.1973; Genetic transformation in Escherichia coli K12. Proceedings of the National Academy of Sciences of the United States of America 70:84–87
GottesmanS.,
GottesmanM.1975b; Excision of prophage lambda in a cell-free system. Proceedings of the National Academy of Sciences of the United States of America 72:2188–2192
HarmW.,
RupertC. S.1963; Infection of transformable cells of Haemophilus influenzae by bacteriophage and bacteriophage DNA. Zeitschrift für Vererbungslehre 94:336–348
HennerW. D.,
KleberI.,
BenzingerR.1973; Transfection of E. coli spheroplasts. III. Facilitation of transfection and stabilization of spheroplasts by different basic polymers. Journal of Virology 12:741–747
NashH. A.1975b; Integrative recombination of bacteriophage lambda in vitro. Proceedings of the National Academy of Sciences of the United States of America 72:1072–1076
PetersonA.,
RutbergL.1969; Linked transformation of bacterial and prophage markers in Bacillus subtilis 168 lysogenic for bacteriophage ϕ 105. Journal of Bacteriology 98:874–876
QuinnW. G.,
SueokaN.1970; Symmetric replication of the B. subtilis chromosome. Proceedings of the National Academy of Sciences of the United States of America 67:717–723
RutbergL.1971; Heat induction of prophage ϕ 105 in Bacillus subtilis: bacteriophage-induced bidirectional replication of the bacterial chromosome. Journal of Virology 12:9–12
RutbergL.1973; Heat induction of prophage 56105 in Bacillus subtilis: bacteriophage-induced bidirectional replication of the bacterial chromosome. Journal of Virology 12:9–12
RutbergL.,
HochJ. A.,
SpizizenJ.1969; Mechanism of transfection with deoxyribonucleic acid from the temperate Bacillus bacteriophage 56105. Journal of Virology 4:50–57
SchekmanR. W.,
IwayaM.,
BromstrupK.,
DenhardtD. T.1971; The mechanism of replication of ϕ X 174 single-stranded DNA III. An enzymic study of the structure of the replicative form II DNA. Journal of Molecular Biology 57:177–199
ShimadaK.,
WeisbergR. A.,
GottesmanM. E.1972; Prophage lambda at unusual locations. I. Location of the secondary attachment sites and the properties of the lysogens. Journal of Molecular Biology63482–502