Historic nucleic acids isolated by Friedrich Miescher contain RNA besides DNA

2021 ◽  
Vol 402 (10) ◽  
pp. 1179-1185
Author(s):  
Andreas Thess ◽  
Ingmar Hoerr ◽  
Benyamin Yazdan Panah ◽  
Günther Jung ◽  
Ralf Dahm
Keyword(s):  
Molecular Weight ◽  
Nucleic Acid ◽  
Molecular Genetics ◽  
Phosphorus Content ◽  
Cell Types ◽  
Significant Percentage ◽  
Dna And Rna ◽  
Large Molecular Weight ◽  
New Type ◽  
High Phosphorus Content

Abstract One hundred fifty years ago, Friedrich Miescher discovered DNA when he isolated “Nuclein”—as he named it—from nuclei of human pus cells. Miescher recognized his isolate as a new type of molecule equal in importance to proteins. He realised that it is an acid of large molecular weight and high phosphorus content. Subsequently, he discovered Nuclein also in the nuclei of other cell types, realised that it chemically defines the nucleus, and speculated on its role in proliferation, heredity and fertilisation. While now universally recognised as the discoverer of DNA, whether Miescher also discovered RNA has not yet been addressed. To determine whether his isolation also yielded RNA, we first reproduced his historic protocols. Our resulting modern Nuclein contained a significant percentage of RNA. Encouraged by this result, we then analysed a sample of Nuclein isolated by Miescher from salmon sperm. Assuming that the RNA present in this sample had degraded to nucleobases, we tested for the presence of uracil in the historic Nuclein. Detection of significant levels of uracil by LC-UV-MS demonstrates that Miescher isolated both forms of nucleic acid—DNA and RNA—and underlines the fundamental nature of his discovery for the field of molecular genetics.

Introduction

1978 ◽  
Vol 36 (3) ◽  
pp. 543-544
Author(s):  
W. Bernard
Keyword(s):  
Molecular Weight ◽  
Electron Microscope ◽  
Nucleic Acid ◽  
Gene Mapping ◽  
Molecular Genetics ◽  
Cell Biology ◽  
Gene Activity ◽  
Close Connection ◽  
Basic Information ◽  
Simple Systems

In comparison to many other fields of ultrastructural research in Cell Biology, the successful exploration of genes and gene activity with the electron microscope in higher organisms is a late conquest. Nucleic acid molecules of Prokaryotes could be successfully visualized already since the early sixties, thanks to the Kleinschmidt spreading technique - and much basic information was obtained concerning the shape, length, molecular weight of viral, mitochondrial and chloroplast nucleic acid. Later, additonal methods revealed denaturation profiles, distinction between single and double strandedness and the use of heteroduplexes-led to gene mapping of relatively simple systems carried out in close connection with other methods of molecular genetics.

scholarly journals Morphological and Chemical Studies of the Spores and Parasporal Bodies of Bacillus laterosporus

1958 ◽  
Vol 4 (5) ◽  
pp. 639-650 ◽  
Author(s):  
Philip C. Fitz-James ◽  
I. Elizabeth Young
Keyword(s):  
Electron Microscopy ◽  
Amino Acids ◽  
Nucleic Acid ◽  
Total Nitrogen ◽  
Phosphorus Content ◽  
Bacillus Species ◽  
Chemical Studies ◽  
Bacillus Laterosporus ◽  
Total P ◽  
High Phosphorus Content

Spores of Bacillus laterosporus were studied to determine the chemical and morphological nature of their basophilic canoe-shaped parasporal bodies. An unusually high phosphorus content of these spores compared to other Bacillus species appeared to be associated with the parasporal body. Preparations of these "canoes" still attached to the spore coats were indeed high in phosphorus, but also in nitrogen. They were free of lipide-soluble and nucleic acid phosphorus and stained for protein. Some 50 per cent of the total nitrogen, but only 6 to 10 per cent of the total P were liberated by extraction with alkali-thioglycollate (pH 11.5) or alkali alone (pH 12.2–12.5). Proteinaceous material was recovered from these alkaline extracts and electron microscopy indicated that there had been a marked loss of "canoe" substance. Extraction with acid, removed some 80 per cent of the phosphorus associated with the "canoes" as orthophosphate. Chromatographic analyses for amino acids indicated some 14 ninhydrin-positive spots in the canoe-coat preparations whereas the whole spores contained at least 16.

scholarly journals Nucleic acids as cofactors for factor XI and prekallikrein activation: Different roles for high-molecular-weight kininogen

2017 ◽  
Vol 117 (04) ◽  
pp. 671-681 ◽  
Author(s):  
Ivan Ivanov ◽  
Ruhama Shakhawat ◽  
Mao-fu Sun ◽  
S. Kent Dickeson ◽  
Cristina Puy ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Nucleic Acid ◽  
Nucleic Acids ◽  
High Molecular Weight ◽  
Inhibitory Effect ◽  
Negative Regulator ◽  
High Molecular Weight Kininogen ◽  
Contact Activation ◽  
Factor Xi ◽  
Dna And Rna

SummaryThe plasma zymogens factor XI (fXI) and prekallikrein (PK) are activated by factor XIIa (fXIIa) during contact activation. Polyanions such as DNA and RNA may contribute to thrombosis and inflammation partly by enhancing PK and fXI activation. We examined PK and fXI activation in the presence of nucleic acids, and determine the effects of the cofactor high molecular weight kininogen (HK) on the reactions. In the absence of HK, DNA and RNA induced fXI autoactivation. Proteases known to activate fXI (fXIIa and thrombin) did not enhance this process appreciably. Nucleic acids had little effect on PK activation by fXIIa in the absence of HK. HK had significant but opposite effects on PK and fXI activation. HK enhanced fXIIa activation of PK in the presence of nucleic acids, but blocked fXI autoactivation. Thrombin and fXIIa could overcome the HK inhibitory effect on autoactivation, indicating these proteases are necessary for nucleic acid-induced fXI activation in an HK-rich environment such as plasma. In contrast to PK, which requires HK for optimal activation, fXI activation in the presence of nucleic acids depends on anion binding sites on the fXI molecule. The corresponding sites on PK are not necessary for PK activation. Our results indicate that HK functions as a cofactor for PK activation in the presence of nucleic acids in a manner consistent with classic models of contact activation. However, HK has, on balance, an inhibitory effect on nucleic acid-supported fXI activation and may function as a negative regulator of fXI activation.Supplementary Material to this article is available online at www.thrombosis-online.com.

The External Shape of Human γ GI Immunoglobulin from Crystal Sections

1971 ◽  
Vol 29 ◽  
pp. 428-429
Author(s):  
L. W. Labaw
Keyword(s):  
Molecular Weight ◽  
Sodium Phosphate ◽  
Osmium Tetroxide ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
X Ray ◽  
Large Molecular Weight ◽  
Cell Dimensions ◽  
Unit Cell Dimensions ◽  
Crystallographic Axes

Crystals of a human γGl immunoglobulin have the external morphology of diamond shaped prisms. X-ray studies have shown them to be monoclinic, space group C2, with 2 molecules per unit cell. The unit cell dimensions are a = 194.1, b = 91.7, c = 51.6Å, 8 = 102°. The relatively large molecular weight of 151,000 and these unit cell dimensions made this a promising crystal to study in the EM.Crystals similar to those used in the x-ray studies were fixed at 5°C for three weeks in a solution of mother liquor containing 5 x 10-5M sodium phosphate, pH 7.0, and 0.03% glutaraldehyde. They were postfixed with 1% osmium tetroxide for 15 min. and embedded in Maraglas the usual way. Sections were cut perpendicular to the three crystallographic axes. Such a section cut with its plane perpendicular to the z direction is shown in Fig. 1.This projection of the crystal in the z direction shows periodicities in at least four different directions but these are only seen clearly by sighting obliquely along the micrograph.

High-resolution nucleic acid sequence mapping via in situ hybridization at the Electron Microscope level

1995 ◽  
Vol 53 ◽  
pp. 752-753
Author(s):  
B.A. Hamkalo ◽  
S. Narayanswami ◽  
A.P. Kausch
Keyword(s):  
Nucleic Acid ◽  
Interphase Nucleus ◽  
Genome Mapping ◽  
Precise Location ◽  
Electron Microscope Level ◽  
Rna Sequences ◽  
Fundamental Interest ◽  
Whole Cells ◽  
Dna And Rna

The availability of nonradioactive methods to label nucleic acids an the resultant rapid and greater sensitivity of detection has catapulted the technique of in situ hybridization to become the method of choice to locate of specific DNA and RNA sequences on chromosomes and in whole cells in cytological preparations in many areas of biology. It is being applied to problems of fundamental interest to basic cell and molecular biologists such as the organization of the interphase nucleus in the context of putative functional domains; it is making major contributions to genome mapping efforts; and it is being applied to the analysis of clinical specimens. Although fluorescence detection of nucleic acid hybrids is routinely used, certain questions require greater resolution. For example, very closely linked sequences may not be separable using fluorescence; the precise location of sequences with respect to chromosome structures may be below the resolution of light microscopy(LM); and the relative positions of sequences on very small chromosomes may not be feasible.

scholarly journals Sulfur Modification in Natural RNA and Therapeutic Oligonucleotides

2021 ◽  
Author(s):  
Ya Ying Zheng ◽  
Ying Wu ◽  
Thomas Begley ◽  
Jia Sheng
Keyword(s):  
Nucleic Acid ◽  
Dna And Rna ◽  
Sulfur Modification ◽  
Oxygen Atoms

Sulfur modifications have been discovered on both DNA and RNA. Sulfur substitution of oxygen atoms at nucleobase or backbone locations in the nucleic acid framework led to a wide variety...

scholarly journals Dramatic nucleolar dispersion in the salivary gland of Schwenkfeldina sp. (Diptera: Sciaridae)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
José Mariano Amabis ◽  
Eduardo Gorab
Keyword(s):  
Salivary Gland ◽  
Transcriptional Activity ◽  
Relative Proportion ◽  
Extreme Case ◽  
Cell Types ◽  
Chromosome Length ◽  
Chromosomal Distribution ◽  
Dna And Rna ◽  
Polytene Nuclei ◽  
Chromosome Regions

AbstractMicronucleoli are among the structures composing the peculiar scenario of the nucleolus in salivary gland nuclei of dipterans representative of Sciaridae. Micronucleolar bodies contain ribosomal DNA and RNA, are transcriptionally active and may appear free in the nucleoplasm or associated with specific chromosome regions in salivary gland nuclei. This report deals with an extreme case of nucleolar fragmentation/dispersion detected in the salivary gland of Schwenkfeldina sp. Such a phenomenon in this species was found to be restricted to cell types undergoing polyteny and seems to be differentially controlled according to the cell type. Furthermore, transcriptional activity was detected in virtually all the micronucleolar bodies generated in the salivary gland. The relative proportion of the rDNA in polytene and diploid tissues showed that rDNA under-replication did not occur in polytene nuclei suggesting that the nucleolar and concomitant rDNA dispersion in Schwenkfeldina sp. may reflect a previously hypothesised process in order to counterbalance the rDNA loss due to the under-replication. The chromosomal distribution of epigenetic markers for the heterochromatin agreed with early cytological observations in this species suggesting that heterochromatin is spread throughout the chromosome length of Schwenkfeldina sp. A comparison made with results from another sciarid species argues for a role played by the heterochromatin in the establishment of the rDNA topology in polytene nuclei of Sciaridae.

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