SOME OBSERVATIONS ON THE EFFECT OF COLCHICINE UPON
            <i>SALMONELLA TYPHOSA</i>

Minsavage, Edward J.; DeLamater, Edward D.

doi:10.1128/jb.70.5.501-509.1955

Cited by 5 publications

(2 citation statements)

References 17 publications

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“…bacterial forms in which the diagnosis of the polyploid nature was based largely or entirely on 105cytological evidence. Thus DeLamater et al (1953) and Minsavage and DeLamater (1955) have reported the production of transient Figure 5. Frequency of ultraviolet induced Ti (1956) have shown that chromatin bodies may phage resistant mutations in 82/r and P6.…”

Section: X-ray Dose In Krmentioning

confidence: 93%

ISOLATION AND CHARACTERIZATION OF A LARGE CELL POSSIBLY POLYPLOID STRAIN OF ESCHERICHIA COLI

Ogg

Zelle

1957

J Bacteriol

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A constantly increasing spectrum of bacterial mutations is under active investigation and the utility of bacterial mutation systems in studies of mutagenesis has been amply demonstrated. Once bacteria were considered to be asexually reproducing organisms, but today at least three distinct mechanisms of gene recombination are known. The last decade has seen the introduction of many new techniques and new ideas into bacterial cytology, and although substantial progress may have resulted, there still is no general agreement as to the detailed structure and composition of the bacterial nucleus (De-Lamater, 1954; Knaysi, 1956; Robinow, 1956). Indeed, an active controversy is in progress concerning the presence or absence of a mitotic cycle similar to that in higher organisms and the organization of the chromatinic material into discrete chromosomes which behave during division as do chromosomes in higher plants and animals. Lederberg et al. (1951) made comparative cytological studies of strains of Escherichia coli K-12 known to be haploid and diploid on the basis of genetic evidence. Although they observed certain characteristic differences in the cytological appearances of the two strains, their preparations did not permit any clear interpretation in terms of doubled chromosomes. A correlation between the ratio of uninucleate and multinucleate E. coli strain B and E. coli strain B/r cells in different portions of the growth curve and the ratio of intact to sectored lactosenegative, ultraviolet induced mutant colonies was observed by Witkin (1951) who also noted a correspondence between the modal number of nuclei per cell in her different samples and the modal size of mutant sector. Her observations 1 This work has been supported jointly by Cornell University and the Atomic Energy Commission through research contract No. AT(30-1)-1244.

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