Nucleic Acid Content and Distribution of Chromosome Number in Original and Sublines of Two Mouse Ascites Tumours

Colter, John S.; Bird, Harris H.; Koprowski, Hilary; Ritter, Hilda B.

doi:10.1038/177993a0

Cited by 6 publications

(1 citation statement)

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“…The first of these gen eralizations has received renew�d confirmation and extension by histo photometric studies of guinea pig (81), rat (104), and mouse (168) diploid nuclei, and by chemical assay of Yoshida sarcoma cells (127). Changes in chromosome number among such related groups as the ass, horse, and mule (298), sublines of two mouse ascites tumors (65), and various tumors and their normal counterparts (230), are paralleled by the amount of DNA per nucleus. The dependence of DNA content on the degree of polyploidy is shown in human liver, which exhibits nuclei of up to octaploid value with increasing age of the individual (284), and in a haploid-diploid species with still higher degrees of polyploidy (239).…”

Section: Concentration In Cells and Compositionmentioning

confidence: 99%

The Nucleic Acids

Cohn¹,

Volkin²

1957

Annu. Rev. Biochem.

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Previous reviews of this topic have summarized progress in the biosyn thesis (43), preparation (5), an d organic chemistry of nucleic acids and nucleotides (37). This essay is concerned with recent work that deals with nucleic acid structure, relation to physiological and metabolic events, and biological interventions. The large increase in the number of published papers is met by an attempt to summarize rather than to expound'in detail. STRUCTURE AND CHEMISTRYThe ability to prepare DNA from various sources in a more purified and less degraded form and ever-increasing apparent molecular weight (100), coupled with an appreciation of the roles of hydrogen bonding and internal charge distribution, which underlie the structure proposed by Watson & Crick (305), have inspired re-examinations of the physicochemical charac teristics of DNA with improved methodology.Titration.-More accurate determination of the pC' values of the effec tive groups in herring sperm DNA by Cox et al. (71) indicates essentially no phosphoryl titration in the neutral range, which eliminates consideration of secondary phosphoryl end groups and thus the need to invoke triply esteri fied phosphate. The hysteresis (difference between forward and backward titrations) in the titration of both herring sperm (71) and thymus (48, 166) DNA is ascribed to the normal (A to T, C to G) hydrogen bonding, which is eliminated at the extremes of pH, in accordance with theory. The increase in ultraviolet absorption (hyperchromic effect) and bathochromic shift in the spectrum after DNA has been carried to pH 2 or 13 is also in accord (191). It has been indicated by Cavalieri & Rosenberg (46) that the ac ceptance of a proton by guanine, the apparent pK of which varies consider ably with ionic strength (46, 166), may cause rearrangements in the purine that result in breaking both guanine-cytosine hydrogen bonds. The same reaction is held accountable by Cavalieri et al. for a spectrophotometrically 1 The survey of the literature pertaining to this review was completed in Novem ber, 1956.2 The following standard abbreviations are employed: RNA and DNA for the ribo-and deoxyribonucleic acids; A, G, C, MC, D, and T for adenine, guanine, cytosine, methylcytosine, uracil, and thymine; AMP, ADP, etc., for the corresponding nucleoside 5'-phosphates and -pyrophosphates; and TMV for tobacco mosaic virus.• Our thanks are due to Dr. K. Sebesta, of the Czechoslovak Academy of Sciences, for critical sum�ries of pertinent papers appearing in some forty journals of Central European countries. 4 Manuscript prepared under Contract No. W-7405-eng-26 for the Atomic Energy Commission. 491 Annu. Rev. Biochem. 1957.26:491-522. Downloaded from www.annualreviews.org Access provided by University of Western Ontario on 02/07/15. For personal use only. Quick links to online content Further ANNUAL REVIEWS

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Section: Concentration In Cells and Compositionmentioning

confidence: 99%