Transforming Activity of Deoxyribonucleic Acid labelled with 5-Bromouracil

Szybalski, Waclaw; Opara-Kubinska, Z.; Lorkiewicz, Z.; Ephrati-Elizur, Erela; Zamenhof, Stephen

doi:10.1038/188743a0

Cited by 42 publications

(9 citation statements)

References 9 publications

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“…The extent of BU incorporation obtained in these experiments was greater than that achieved in investigations of the effect of BU on recombination in transformation and conjugation. The normal recombination of BU-containing DNA reported here is consistent with the observations that transformation in Bacillus subtilis was unaffected by the presence of BU in the transforming DNA, when the latter was used at concentrations which did not grossly exceed those required to saturate transformation (Szybalski et al 1960;Gimlin et al 1966). Thus conjugation in Escherichia coli K 12 is the only bacterial genetic system in which BU-substituted donor DNA has been found to affect recombination; Folsome (1960) and Shchipkov & Samoylenko (1966) showed that, following BU treatment of the Hfr, the viable recombinants contained less of the transmitted DNA.…”

Section: Discussionsupporting

confidence: 78%

“…No consistent pattern of results has been established in studies investigating the effect of base-analogue substitution on genetic recombination in bacteria. Low concentrations of unifilar and bifilar BU-labeled DNA did not influence the efficiency of transformation in Bacillus subtilis (Szybalski et al 1960; Gimlin et ul. I 966) although earlier experiments suggested that the number of recombinants was depressed by treatment (Ephrati-Elizur & Zamenhof, 1959).…”

Section: Introductionmentioning

confidence: 99%

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The Recombination of Bromouracil-containing Deoxyribonucleic Acid in Salmonella typhimurium Transduction

WILKINS

1968

Journal of General Microbiology

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SUMMARYSalmonella typhimurium tolerated the replacement of about 70 % of the thymine in the DNA by 5-bromouracil (BU). In phage PLT-22 transduction, the presence of BU in the donor DNA had no effect on the linkage relationship of two contransduced markers and did not conclusively alter the ratio of complete transductants to abortive transductants. The yield of transductants per plaque-forming unit was more than doubled by the treatment of the donor bacteria and phage with BU. However, more than half of the BU-treated phage particles, detected by electron microscopy, did not form plaques; when the multiplicity of infection was calculated from the titre of physical particles, the frequency of transductants was normal. It is concluded that recombination was not affected by the substantial incorporation of BU into the donor DNA. Treatment of the recipient bacteria with BU slightly modified recombination by decreasing the frequency of transductants by about 40 % and the linkage of the cotransduced markers by about 5 %. Because comparable results were not obtained when the donor DNA contained BU, it is suggested that these effects resulted indirectly from the treatment of the recipient bacteria.

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Section: Discussionsupporting

confidence: 78%

Section: Introductionmentioning

confidence: 99%

The Recombination of Bromouracil-containing Deoxyribonucleic Acid in Salmonella typhimurium Transduction

WILKINS

1968

Journal of General Microbiology

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“…Zamenhoj: I could suggest an experiment which would follow along the lines that you have mentioned. If one incorporates 5-bromouracil into DNA having transforming activity (19), and then subject it to Meselson's density gradient centrifugation (72), one eventually comes out with three fractions (peaks) ; that is, one corresponding to molecules without any bromouracil, another one with only one strand labeled, and the third one with two strands labeled. Now, the specific transforming activity of each of these peaks is practically the same.…”

Section: Freese: Yesmentioning

confidence: 99%

Mutations

Schull¹

1962

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PREFACESomewhat over twenty years ago, the Josiah Macy, Jr. Foundation initiated a series of regularly scheduled conferences directed toward challenging problems in medicine and health. With time, firm but not immutable ground rules have been evolved for the conduct of these sessions. Thus, each conference group is to meet annually for a period of five or more years. Twenty-five persons, selected to represent a multidiscipline approach, are to participate in a meeting. These individuals are termed conference members, if they have been selected to participate in all of the meetings of a group, and guests, if they are to participate in a single meeting.The purpose of each conference is the promotion of communication, the exchange of ideas. To this end, an informal give-and-take among the participants, members and guests, is encouraged. Structure and continuity are given the discussion by a leader whose function is to present some of the more interesting aspects of the problem under discussion. The participants are enjoined to interrupt this presentation with questions, criticisms, and comment. At their best, the interruptions lay bare the birth and maturation of an idea, and form, therefore, an essential part of the lessons to be gained from the conference process. To share these lessons as widely as possible, an edited transcript of the meeting is published. These transactions, which attempt to retain the spontaneity of the discussion, have aroused considerable interest and criticism. Comments range from an enthusiasm for, to a total rejection of, the personalized approach. Criticism, in the words of Frank Fremont-Smith, for many years the guardian of these conferences, "has been directed primarily to editorial permissiveness which has allowed in the final text, in some instances, too many questions, remarks, or comments which, although perhaps useful during a heated discussion, seem out of context and interrupt the sequence of thought." Clearly, not all critics recognize the narrowness of the path twixt spontaneity, on the one hand, and editorial permissiveness, on the other, nor the challenges which confront the editor.

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“…Ephrati-Elizur and Zamenhof (14) found that the transforming activities of four markers were reduced to different degrees when 12% thymine was replaced by bromouracil in Bacillus subtilis. Szybalski et al (36) observed that extensively labeled BU-containing DNA did not affect the transforming activity of the indole locus in B. subtilis. Litman and Szybalski (24) showed that the DNA synthesized from a BUdR-labeled primer with DNA polymerase functioned normally in transformation.…”

mentioning

confidence: 99%

Effect of Iododeoxyuridine upon Conjugation and the Fate of Transferred Deoxyribonucleic Acid in Escherichia coli K-12

et al. 1971

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The incorporation of 5-iododeoxyuridine (IUdR) into Escherichia coli K-12 deoxyribonucleic acid (DNA) has been found to decrease significantly the viability of female strains A288 and JC41 1r but to have only minor effect upon their ability to act as conjugational recipients and to perform recombination after conjugation. In contrast, IUdR incorporation into male strain HfrC appears to interfere with both chromosome transfer and genetic recombination. By using IUdR to densitylabel female DNA, and carrying out large-scale matings with 3H-thymidine-labeled male cells, we examined the fate of transferred DNA. After a 30-min mafing, the T6-sensitive male cells were lysed, and the DNA of the merozygotes and remaining female cells was isolated. Initial centrifugation of this DNA in a CsCl gradient showed that the male and female DNA species were associated. The nature of this association of the parental DNA species was determined by formaldehyde denaturation followed by CsCl centrifugation. Denaturation of DNA isolated immediately after T6 lysis gave a peak of radioactivity banding at the density of light singlestranded DNA. However, denaturation of DNA isolated after T6 lysis and dilution of the cells into fresh medium, exhibited peaks of radioactivity banding at positions corresponding to single-stranded, density-labeled DNA. The results indicate that recombination after conjugation in E. coli takes place by a breakage-and-reunion mechanism. The process of recombination can be separated into two stages. In the first stage, the donor and recipient DNA molecules become associated. The second stage consists of the formation of phosphodiester bonds between the donor and recipient segments comprising the recombinant molecule.

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Transforming Activity of Deoxyribonucleic Acid labelled with 5-Bromouracil

Cited by 42 publications

References 9 publications

The Recombination of Bromouracil-containing Deoxyribonucleic Acid in Salmonella typhimurium Transduction

The Recombination of Bromouracil-containing Deoxyribonucleic Acid in Salmonella typhimurium Transduction

Mutations

Effect of Iododeoxyuridine upon Conjugation and the Fate of Transferred Deoxyribonucleic Acid in Escherichia coli K-12

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