Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| mechanism of transcription in the n operon of bacteriophage lambda. | 1972 | 4560678 | |
| plasmid-controlled variation in the content of methylated bases in bacteriophage lambda deoxyribonucleic acid. | the n(6)-methyladenine (meade) and 5-methylcytosine (mec) contents in deoxyribonucleic acid (dna) of bacteriophage lambda has been analyzed as a function of host specificity. the following facts have emerged: (i) lambda grown on strains harboring the p1 prophage contain ca. 70 more meade residues/dna molecule than lambda grown either in the p1-sensitive parent, or in a p1 immune-defective lysogen which does not confer p1 modification; (ii) lambda grown on strains harboring the n-3 drug-resistanc ... | 1972 | 4561202 |
| degradation of bacteriophage lambda deoxyribonucleic acid after restriction by escherichia coli k-12. | wild-type bacteria which restrict the deoxyribonucleic acid (dna) of infecting phage when the phage do not carry the proper host modification rapidly degrade that restricted dna to acid-soluble products. the purified restriction enzyme acts as an endonuclease in vitro to cleave restrictable dna and does not further degrade the dna fragments produced. we have examined mutants of escherichia coli k-12 which lack various nucleases in order to determine which nucleases are involved in the rapid acid ... | 1972 | 4562392 |
| interaction of the recombination pathways of bacteriophage lambda and host escherichia coli: effects on lambda recombination. | 1972 | 4563260 | |
| interaction of the recombination pathways of bacteriophage lambda and its host escherichia coli k12: effects on exonuclease v activity. | 1972 | 4563261 | |
| behavior of coliphage lambda in shigella flexneri 2a. | the insensitivity of wild-type shigella flexneri 2a to coliphage lambda is a consequence of its native genetic defect in the mala gene cluster. the "smooth" s. flexneri 2a lipopolysaccharide layer affects the efficient adsorption of lambda. derivatives, capable of serving as functional hosts for lambda, were obtained by repairing the mala lesion, enabling the expression of the malb-lambdarcp region of s. flexneri. introduction of a mutation into s. flexneri causing a "rough" lipopolysaccharide c ... | 1972 | 4563593 |
| formation of hybrids between coliphage lambda and salmonella phage p22 with a salmonella typhimurium hybrid sensitive to these phages. | an unusual salmonella typhimurium hybrid with sensitivity to coliphage lambda and salmonella phage p22 has been recovered from matings between an escherichia coli k-12 hfr donor and an s. typhimurium recipient. the hybrid is an excellent host for achieving genetic recombination between lambda and p22. two broad classes of hybrid phages were isolated. the lambda-p22 hybrid class, which has the protein coat of lambda, contains at least the c region of p22. the p22-lambda hybrid class has the prote ... | 1972 | 4564201 |
| precursor and product in bacteriophage lambda recombination. | analyses of the time of recombination in bacteria infected with phage lambda and in spheroplasts infected with purified phage lambda dna indicate a preponderance of recombination occurring before replication ("early recombination") after infection with tandem dimers formed in vitro compared to linear monomer dna and phage infections. among the early recombinants is a large fraction of cells that produces one recombinant type exclusively. two suggestions are discussed-that a dimer-like molecule i ... | 1972 | 4564207 |
| fine-structure deletion map of the escherichia coli l-arabinose operon. | a fine-structure deletion map of the l-arabinose operon of e. coli was constructed by mapping deletion endpoints against point mutations. of 350 independent deletions with average endpoint separation of ten nucleotides, 51 ended in the control region between the c and b genes, and the rest ended in the structural genes a, b, c, and d. if deletion endpoints are randomly distributed, the c and b genes are separated by about 510 nucleotides. deletion endpoints and locations of point mutations in fa ... | 1972 | 4564212 |
| methylation pattern of lambda deoxyribonucleic acid. | deoxyribonucleic acid (dna) extracted from phage lambda grown on escherichia coli k-12 strain w4032 had 113 +/- 10 5-methylcytosine residues and 215 +/- 20 6-methyl adenine residues per genome, as determined by three independent methods. these methylated nucleotides were distributed equally among the two strands of lambda dna. shearing of double-stranded dna to half-length fragments revealed a slight deficiency of 5-methyl cytosine in the 55% guanine plus cytosine half. shearing the dna to fragm ... | 1972 | 4564587 |
| purification and properties of d protein: a transcription factor of escherichia coli. | d factor is protein that stimulates dna transcription in vitro by rna polymerase. for dna from bacteriophage lambda, we present evidence that d protein interacts with dna to increase the frequency and improve the specificity of initiation by rna polymerase. | 1972 | 4566455 |
| lambda phage dna: joining of a chemically synthesized cohesive end. | the chemically synthesized dodecamer d(pa-g-g-t-c-g-c-c-g-c-c-c) was annealed, and was covalently joined to lambda phage dna with bacterio-phage t(4) ligase. the 5'-end of the dodecamer was joined to a deoxyguanosine residue. repair with dna polymerase i established that the position of joining was the left-hand end of lambda dna. this is the first time that a chemically synthesized oligonucleotide has been covalently joined to a naturally occurring dna molecule. | 1973 | 4566655 |
| polar mutations in lac, gal and phage lambda consist of a few is-dna sequences inserted with either orientation. | 1972 | 4567156 | |
| interference with the expression of the n gene function of phage lambda in a mutant of escherichia coli. | 1973 | 4567743 | |
| an endonuclease induced by bacteriophage lambda. | 1973 | 4567785 | |
| regulation of the expression of the n gene of bacteriophage lambda. | a quantitative assay for the n protein of bacteriophage lambda has been used to study the in vivo regulation of n gene expression. the assay makes use of the observation that in a cell-free protein-synthesizing system from escherichia coli programmed with lambdan(-) dna the lambda endolysin is made only if n protein is added to the reaction. the rate of synthesis of n protein in vivo is negatively controlled by the products of the ci and tof genes of the phage. furthermore, n protein activity is ... | 1973 | 4568728 |
| indirect ultraviolet induction and curing in e. coli cells lysogenic for bacteriophage lambda. | 1973 | 4568843 | |
| factors influencing competence of escherichia coli for lambda-phage deoxyribonucleic acid infection. | 1972 | 4569211 | |
| host specificity of salmonella typhimurium deoxyribonucleic acid restriction and modification. | the restriction and modification genes of salmonella typhimurium which lie near the thr locus were transferred to a restrictionless mutant of escherichia coli. these genes were found to be allelic to the e. coli k, b, and a restriction and modification genes. e. coli recombinants with the restriction and modification host specificity of s. typhimurium restricted phage lambda that had been modified by each of the seven known host specificities of e. coli at efficiency of plating levels of about 1 ... | 1973 | 4570605 |
| bacterial cell division regulation: lysogenization of conditional cell division lon - mutants of escherichia coli by bacteriophage. | the lon(-) mutants of escherichia coli grow apparently normally except that, after temporary periods of inhibition of deoxyribonucleic acid synthesis, septum formation is specifically inhibited. under these conditions, long, multinucleate, nonseptate filaments result. the lon(-) mutation also creates a defect such that wild-type bacteriophage lambda fails to lysogenize lon(-) mutants efficiently and consequently forms clear plaques on a lon(-) host. two lines of evidence suggest that this failur ... | 1973 | 4570782 |
| characterization of the mrna transcribed from the head and tail genes of phage lambda chromosome. | 1973 | 4573271 | |
| lysogenization by bacteriophage lambda. i. multiple infection and the lysogenic response. | 1973 | 4573866 | |
| e. coli mutants produced by the insertion of bacteriophage lambda dna. | 1973 | 4576121 | |
| genetic recombination induced by dna cross-links in repressed phage lambda. | 1973 | 4576122 | |
| excretion of enterochelin by exba and exbb mutants of escherichia coli. | escherichia coli mutants that are insensitive to colicins b and i hyperproduce and excrete the iron chelator enterochelin, which is an inhibitor of these colicins. these mutants are classified as exba and exbb. the exba mutants are chromium sensitive and require iron for growth, and the mutations are located in the tonb region at min 25 of the e. coli chromosome. tonb mutants in which the genome of phage lambda is inserted into the bacterial chromosome within the tonb gene also exhibit enteroche ... | 1973 | 4576403 |
| comparison of the resa1 and pola1 mutations in isogenic strains of escherichia coli k-12. | strains carrying either the pola1 or resa1 mutation are deficient in dna polymerase i, and the pola1 and resa1 mutations do not complement in merozygotes. the effect of these mutations in otherwise identical genetic backgrounds was studied: after ultraviolet irradiation both strains degrade their dna more rapidly and more extensively than the wild-type strains. however, after x-ray irradiation the resa1 strain shows little dna breakdown and repairs its single-strand breaks. in contrast, the pola ... | 1973 | 4576410 |
| prophage induction by high temperature in thermosensitive dna mutants lysogenic for bacteriophage lambda. | high-temperature treatment of thermosensitive dna mutants lysogenic for phage lambda leads to prophage induction and release of phage (at the permissive temperature) in elongation-defective mutants of the genotypes dnab, dnae, and dnag. in initiation-defective mutants no prophage induction occurs at 42 c in mutants of the genotype dnaa, whereas with a dnac mutant as well as with strain hfrh 252 (map position not yet known) phages are released at 42 c. dna degradation at the replication fork at 4 ... | 1973 | 4576518 |
| [bacteriophage lambda dna-dependent synthesis of endolysin in a membranous cell-free system of e. coli]. | 1973 | 4576624 | |
| intermediates in the maturation of bacteriophage lambda dna. | 1973 | 4576745 | |
| a sedimentation analysis of dna found in escherichia coli infected with phage lambda mutants. | 1973 | 4576746 | |
| replicator mutants of bacteriophage lambda: characterization of two subclasses. | 1973 | 4576747 | |
| bacteriophage lambda dna synthesized by mutants in gene n. | 1973 | 4576748 | |
| ultraviolet reactivation of lambda phage: assay of infectivity of dna molecules by spheroplast transfection. | 1973 | 4577040 | |
| properties of a mutant of escherichia coli defective in bacteriophage lambda head formation (groe). i. initial characterization. | 1973 | 4578098 | |
| properties of a mutant of escherichia coli defective in bacteriophage lambda head formation (groe). ii. the propagation of phage lambda. | 1973 | 4578099 | |
| host participation in bacteriophage lambda head assembly. | 1973 | 4578100 | |
| isolation of a ribonuclease associated with the formation of phage lambda-ci. | 1973 | 4578800 | |
| structural change of dna during lambda-phage lysogenization and induction. | 1973 | 4579423 | |
| role of dna topology in transcription of coliphage lambda in vivo. ii. dna topology protects the template from exonuclease attack. | 1973 | 4579547 | |
| incisions in ultraviolet irradiated circular bacteriophage lambda dna molecules in excision proficient and deficient lysogens of e. coli. | 1973 | 4579985 | |
| the role of c3 product and anti-immunity in zygotic induction of bacteriophage lambda. | 1973 | 4580270 | |
| replication of bacteriophage lambda dna dependent on the function of host and viral genes. i. interaction of red, gam and rec. | 1973 | 4580674 | |
| an analysis of the processes of infection and induction of e. coli mutant hfl-1 by bacteriophage lambda. | 1973 | 4580731 | |
| postirradiation fate of bacteriophage lambda dna in the host cell. | 1973 | 4580735 | |
| physical studies of rna involvement in bacteriophage lambda dna replication and prophage excision. | 1973 | 4580911 | |
| requirement for transcription in the neighborhood of the phage attachment region for lysogenization of escherichia coli by bacteriophage lambda. | 1973 | 4580912 | |
| distinct effects of diamines, polyamines, and magnesium ions on the stability of lambda phage heads. | 1973 | 4581784 | |
| repair of gamma-ray-induced damage in bacteriophage lambda. | 1973 | 4582608 | |
| influence of thymine starvation on the integrity of episomal and chromosomal deoxyribonucleic acids in escherichia coli cr34 (lambda ind-). | the effect of thymine deprivation on the integrity of phage lambda, sex factor, and chromosomal deoxyribonucleic acid (dna) in escherichia coli cr34 (lambda ind(-)) was examined by sedimenting cell lysates through alkaline sucrose gradients. both sex factor and chromosomal dnas showed evidence of being degraded during the starvation period. in contrast, no loss of closed circular lambda dna was observed. | 1973 | 4583234 |
| a new effect of the rex gene of phage lambda: premature lysis after infection by phage t1. | 1973 | 4583305 | |
| genetic characterization of a prm- mutant of bacteriophage lambda. | 1973 | 4583306 | |
| loss of an essential function of escherichia coli by deletions in the thya region. | in an attempt to obtain deletions in the thya gene, an abnormal lysogen of lambda having the prophage inserted between the thya and lysa genes was induced, and the surviving cured cells were examined for thy(-) and lys(-) mutants. in nearly 10,000 cured cells, 184 lys(-) but no thy(-) mutants were found. at the same time, the induced lambda phage contained an approximately equivalent number of lambdathya(+) and lambdalysa(+) transducing particles. by contrast, in a strain with the genotype f' th ... | 1973 | 4584799 |
| infection of escherichia coli envelope-membrane complex with lambda phage: adsorption and penetration. | 1973 | 4585981 | |
| fate of bacteriophage lambda in non-immune germ-free mice. | 1973 | 4586796 | |
| role of the cro gene in bacteriophage lambda development. | 1973 | 4587402 | |
| prophage lambda at unusual chromosomal locations. ii. mutations induced by bacteriophage lambda in escherichia coli k12. | 1973 | 4587404 | |
| malb region in escherichia coli k-12: characterization of new mutations. | phenotypic characterization and mapping of more than 50 mal(-) mutations located in the malb region lead one to divide the site for mal(-)lambdas mutations (formerly called gene malb) in that region, into two adjacent genetic segments malj and malk. malj and malk are both involved in maltose permeation. it is suggested that (i) malk and lamb, the only known gene specifically involved in phage lambda adsorption (20), constitute an operon of polarity malk lamb. (ii) malj and malk correspond to two ... | 1974 | 4587612 |
| [induction of mutations and repairs in a lambda phage--e. coli system following ultraviolet irradiation]. | 1973 | 4589269 | |
| radiochemical purification of bacteriophage lambda integrase. | 1974 | 4589454 | |
| indirect ultraviolet-reactivation of phage lambda. | when an f(-) recipient escherichia coli k12 bacterium receives hfr or f-lac(+) dna from an ultraviolet-irradiated donor, its capacity to promote dna repair and mutagenesis of ultraviolet-damaged phage lambda is substantially increased. we call this phenomenon indirect ultraviolet-reactivation, since its features are essentially the same as those of ultraviolet-reactivation; this repair process occurs in pyrimidine dimer excision-deficient strains and produces clear plaque mutations of the restor ... | 1974 | 4589889 |
| divergent orientation of transcription from the arginine gene ecbh cluster of escherichia coli. | ribonucleic acid (rna) isolated from escherichia coli w3350 (f(-), arge(+)c(+)b(+)h(+)), in the absence of l-arginine, hybridizes with the separated leftward (l) and rightward (r) transcribing strands of the arginine transducing phage hphi80darge(+)c(+)b(+)h(+)ppc(+)imm(lambdaci857) deoxyribonucleic acid (dna) with a ratio of 30:70, respectively. in the presence of l-arginine and its intermediates, l-ornithine and l-citrulline, rna transcriptions from both the strands of the argecbh cluster were ... | 1974 | 4590481 |
| transfection of escherichia coli spheroplasts. ii. relative infectivity of native, denatured, and renatured lambda, t7, t5, t4, and p22 bacteriophage dnas. | the change of infectivity of phage dnas after heat and alkali denaturation (and renaturation) was measured. t7 phage dna infectivity increased 4- to 20-fold after denaturation and decreased to the native level after renaturation. both the heavy and the light single strand of t7 phage dna were about five times as infective as native t7 dna. t4 and p22 phage dna infectivity increased 4- to 20-fold after denaturation and increased another 10- to 20-fold after renaturation. these data, combined with ... | 1973 | 4591046 |
| genetic analysis of bacteriophage lambda strains which transduce the genes for leucine biosynthesis. | 1973 | 4591366 | |
| size distribution and molecular polarity of newly replicated dna in escherichia coli. | newly synthesized dna, in e. coli lysogenic for the phage lambda, was labeled by short pulses of [(3)h]-thymidine, isolated, and separated on the basis of size by alkaline sucrose density gradient centrifugation. the molecular polarity of this dna was determined by hybridization with each of the separated strands of lambda dna. the results show that, in the 3' to 5' direction, replication proceeds by synthesis of short chains that are subsequently joined to long dna. this is true for both a pola ... | 1974 | 4592688 |
| interaction of bacterial and lambda phage recombination systems in the x-ray sensitivity of escherichia coli k-12. | e. coli cells lysogenic for the thermoinducible prophage lambdaci857 can be transiently induced by a brief heat treatment. although this treatment does not kill the cells, some lambda products normally formed during vegetative phage development are made that can alter the response of host cells to x-irradiation by causing an increase in radioresistance. this increased resistance is particularly striking in the recombination-deficient recb-strain, which is normally much more radiosensitive than i ... | 1974 | 4592694 |
| regulation of bacteriophage lambda development. | 1973 | 4593172 | |
| control of gene expression in bacteriophage lambda. | 1973 | 4593306 | |
| evidence that pretreatment of escherichia coli cells with n-methyl-n'-nitro-n-nitrosoguanidine enhances mutability of subsequently infecting phage lambda. | 1973 | 4593995 | |
| on maturation of the bacteriophage lambda chromosome. | 1973 | 4594001 | |
| [study of the characteristics of lambda phage dna transfection in e. coli cells treated with cacl2. the role of ca2+ ions at various stages of phage transfection]. | 1973 | 4594845 | |
| genetic characterization of a bacterial locus involved in the activity of the n function of phage lambda. | 1974 | 4595374 | |
| initiation and regulation of transcription in coliphage lambda. | 1974 | 4595839 | |
| preparation of plasmid lambda dv from bacteriophage lambda: role of promoter-operator in the plasmid replicon. | a technique has been described for selection of bacteria carrying plasmid lambdadv. with this technique, the effects of mutations in the promoter-operators were compared on the production and perpetuation of the plasmid. it was found that "left" promoter-operator that controls leftward gene expressions can be deleted from the plasmid genome. some mutations of "right" promoter-operator (pror) that controls expression of genes tof, o, and p affect the stability of the plasmid. however, the plasmid ... | 1974 | 4595898 |
| dna polymerase i-dependent mutants of coliphage lambda. | mutagenized lysates of bacteriophage lambda were screened for mutants unable to plate on dna polymerase i-deficient (pola(-)) hosts. the mutants obtained were all recombination deficient (red(-)). these mutants, like red(-) and gam(-) mutants previously isolated by others, grow more poorly than wild-type lambda even on pola(+) hosts (burst size 14 to 30% of wild-type lambda.) in a pola(-) host, the burst size of red(-) and gam(-) mutants is reduced an additional five- to tenfold, and lysis is de ... | 1974 | 4596297 |
| conversion of murein to non-reducing fragments by enzymes from phage lambda and vi ii lysates. | 1974 | 4596398 | |
| promoters are in the operators in phage lambda. | 1974 | 4598033 | |
| requirement for maturation of escherichia coli bacteriophage lambda. | 1974 | 4598360 | |
| bacteriophage lambda derivatives carrying two copies of the cohesive end site. | 1974 | 4598361 | |
| duplication of the bacteriophage lambda cohesive end site: genetic studies. | 1974 | 4598362 | |
| a conditional lethal mutant of escherichia coli k12 defective in the 5' leads to 3' exonuclease associated with dna polymerase i. | a mutant strain of e. coli, initially identified by an abnormally high frequency of recombination, has been found to be defective in the 5' --> 3' exonuclease associated with dna polymerase i, but not in the polymerase activity. this defect is tolerated at 30 degrees , but is lethal at 43 degrees . like other polymerase i mutants, the strain is unusually sensitive to methyl methanesulfonate and to ultraviolet irradiation; it is also unable to support the growth of phage lambda defective in gener ... | 1974 | 4600786 |
| regulation of developmental pathways following infection of escherichia coli by bacteriophage lambda. | 1974 | 4601262 | |
| restriction in the number of infecting lambda phage genomes that can participate in intracellular growth. | 1974 | 4601459 | |
| activity of empty, headlike particles for packaging of dna of bacteriophage lambda in vitro. | a precursor head of phage lambda is synthesized after induction of cells lysogenic for lambdad(-)f(-) and lambdaa(-) (head-defective) mutants. this precursor head can be assayed by complementation in vitro and can be purified by cscl gradient centrifugation and sucrose gradient sedimentation. the precursor head contains no dna and has the same dimensions as the petit lambda particle. it can be packed with lambda dna in an extract from induced escherichia coli lysogenic for a lambdae(-) mutant. | 1974 | 4601587 |
| release of polarity in escherichia coli by gene n of phage lambda: termination and antitermination of transcription. | the induction of lambda prophage provokes the constitutive expression of the adjacent gal operon in e. coli. this "escape synthesis" can result from transcription that initiates at a phage promoter and extends into the gal operon. the effect requires the product of the lambda gene n. n-mediated transcription not only fails to terminate at the prophage-bacterial junction and at the ends of bacterial operons, but ignores termination signals caused by polar insertions or ochre mutations within gal. ... | 1974 | 4601822 |
| isolation of a specialized transducing bacteriophage lambda carrying the polc locus of escherichia coli. | we have isolated a specialized transducing phage carrying the polc locus of e. coli k-12. a strain of e. coli lacking the lambda attachment site was infected with bacteriophage lambda. lysogens carrying lambda at the tona locus were isolated by selecting lambda-immune, t5-resistant strains. transducing phages of dapc, dapd and polc, which map within 0.2 min of tona, were obtained in lysates prepared from two of the lysogens. the isolated phage, lambdadpolc, is defective but can transduce four di ... | 1974 | 4604644 |
| temperature-sensitive modification and restriction phenotypes of an escherichia coli dnad mutant. | a mutant of escherichia coli temperature-sensitive for deoxyribonucleic acid synthesis, dnad, was found to have temperature-sensitive modification and restriction phenotypes. in contrast to the original observation by carl (1970), the mutant could support the growth of lambda phage at 41 c. however, the lambda phages thus produced were able to form plaques with normal plating efficiency only on e. coli c, a restriction-less strain, but not on e. coli k. since the lambda phages produced in the mu ... | 1974 | 4605206 |
| time scale for rejoining of bacteriophage lambda deoxyribonucleic acid molecules in superinfected pol+ and pola1 strains of escherichia coli after exposure to 4 mev electrons. | the time scale for rejoining of radiation-induced deoxyribonucleic acid (dna) single-strand breaks was measured in the presence and absence of oxygen. the involvement of dna polymerase i in this repair process was studied. formation and rejoining of dna strand breaks were measured in lambda dna infecting lysogenic pol(+) and pola1 strains of escherichia coli irradiated by 4 mev electrons under identical conditions. irradiation and transfer to alkaline detergent could be completed in less than 18 ... | 1974 | 4605387 |
| fine structure mapping, complementation, and physiology of escherichia coli hfl mutants. | six of seven hfl mutations of escherichia coli k12, characterized by high frequencies of lysogenization by phage lambda and lambdaciii mutants, are shown to be tightly linked to, but not within, the pura locus. all six hfl mutations are recessive to wild type in hfl(+)/hfl merodiploids and all lie in a single complementation group, located just counterclockwise from the pura locus. all six mutations confer a slightly increased resistance to penicillin and rifamycin and a slightly increased sensi ... | 1974 | 4606553 |
| interference with phage lambda cro gene function by a colicin-tolerant escherichia coli mutant. | 1974 | 4606679 | |
| properties of hybrids between salmonella phage p22 and coliphage lambda. | 1974 | 4608090 | |
| n protein causes the lambda dv plasmid to inhibit heteroimmune phage lambda imm434 growth and stimulates lambda dv replication. | 1974 | 4608877 | |
| manipulation of restriction targets in phage lambda to form receptor chromosomes for dna fragments. | 1974 | 4608939 | |
| genes of phage lambda essential for lambda dv plasmids. | 1974 | 4609081 | |
| interaction of escherichia coli o55 hybrids with bacteriophage lambda. a new type of host specificity between escherichia coli o55 and urinary escherichia coli. | 1974 | 4609858 | |
| chemical linkage of the tail to the right-hand end of bacteriophage lambda dna. | 1974 | 4610148 | |
| isolation of a lambda dv plasmid carrying the bacterial gal operon. | a lambdadvgal plasmid carrying genes for controlled plasmid replication from phage lambda and the bacterial gal operon was isolated as a deletion mutant of phage lambdagalq4, which carries the gal operon between lambda genes p and q. the plasmid dna was found in cell extracts as covalently closed circular molecules. the plasmid was characterized by using genetic crosses, digestion with the specific endonuclease ecori, sucrose gradient centrifugation, and electron microscopy. in one clone analyze ... | 1974 | 4610174 |
| new method for large-scale preparation of covalently closed lambda dna molecules. | a combination of mutations in bacteriophage lambda and its host escherichia coli k-12 provides a convenient system for the isolation of large quantities of covalently closed circular dna molecules. we describe two procedures for the large scale preparation of lambda dna in the duplex circular form. | 1974 | 4610176 |
| prophage induction of noninducible coliphage 186. | coliphage 186 has been regarded as a member of the noninducible group of coliphages. evidence that prophage 186 is induced by ultraviolet irradiation or by treatment with nalidixic acid or mitomycin c is now presented. the phage yields were similar to those from lysogens of the inducible phage lambda, and the induction required a reca(+) host. a noninducible mutant of 186 was isolated from its heat-inducible derivative, 186cits, that was no longer inducible by ultraviolet irradiation but remaine ... | 1974 | 4610182 |
| interactions between the vegetative states of phages lambda and t1. | bacteria containing phage lambda in the vegetative state were produced either by induction of lambda lysogens or by infection of sensitive cells with lambda. these cells were superinfected with t1, and assayed for the production of lambda, t1, or both. although most of the cells produced only lambda or t1, approximately 10% of the infectious centers were dual yielders. examination of the progeny phage produced by the population of mixedly-infected cells showed that there was little, if any, phen ... | 1974 | 4610186 |
| role of genetic recombination in dna replication of bacteriophage lambda. i. genetic characterization of the delta gene. | we describe the isolation and genetic characterization of point mutations in gene delta, including a temperature-sensitive mutation (del(206)). genetic methods enable the extraction of a delta mutation from the triple mutant (del,red,gam) and the construction of new genotypes, including del,red and del,gam double mutants. tests of plating efficiency indicate gene delta is essential for normal phase growth on the pola host. the possible association of delta in a system involving alpha, beta, and ... | 1974 | 4610187 |