A unified matrix hypothesis of DNA-directed morphogenesis, protodynamism and growth control1

1989 ◽  
Vol 9 (2) ◽  
pp. 157-188 ◽  
Author(s):  
Klaus Scherrer
Keyword(s):  
Nuclear Dna ◽  
Theoretical Concept ◽  
Structure And Function ◽  
Protein Coding ◽  
Basic Proposition ◽  
C Value ◽  
Eukaryotic Organisms ◽  
And Function ◽  
Chromosome Organisation ◽  
Morphological Patterns

A theoretical concept is proposed, in order to explain some enigmatic aspects of cellular and molecular biology of eukaryotic organisms. Among these are the C-value paradox of DNA redundancy, the correlation of DNA content and cell size, the disruption of genes at DNA level, the “Chromosome field” data of Lima de Faria (Hereditas93:1, 1980), the “quantal mitosis” proposition of Holtzer et al. (Curr. Top. Dev. Biol.7:229 1972), the inheritance of morphological patterns, the relations of DNA and chromosome organisation to cellular structure and function, the molecular basis of speciation, etc. The basic proposition of the “Unified Matrix Hypothesis” is that the nuclear DNA has a direct morphogenic function, in addition to its coding function in protein synthesis. This additional genetic information is thought to be largely contained in the non-protein coding transcribed DNA, and in the untranscribed part of the genome.

A Unified Matrix Hypothesis of DNA-directed morphogenesis, protodynamism and growth control

1988 ◽  
Vol 8 (6) ◽  
pp. 669-669
Author(s):  
Klaus Scherrer
Keyword(s):  
Nuclear Dna ◽  
Growth Control ◽  
Theoretical Concept ◽  
Protein Coding ◽  
Basic Proposition ◽  
C Value ◽  
Eukaryotic Organisms ◽  
And Function ◽  
Chromosome Organisation ◽  
Morphological Patterns

A theoretical concept is proposed, in order to explain some enigmatic aspects of cellular and molecular biology of eukaryotic organisms. Among these are the C-value paradox of DNA redundancy, the correlation of DNA content and cell size, the disruption of genes at DNA level, the “Chromosome field” data of Lima de Faria (Hereditas93:1, 1980), the “quantal mitosis proposition” of Holtzer et al. (Curr. Top. Dev. Biol.7:229, 1972), the inheritance of morphological patterns, the relations of DNA and chromosome organisation to cellular structure and function, the molecular basis of speciation, etc. The basic proposition of the “Unified Matrix Hypothesis” is that the nuclear DNA has a direct morphogenic function, in addition to its coding function in protein synthesis. This additional genetic information is thought to be largely contained in the non-protein coding transcribed DNA, and in the untranscribed part of the genome.

scholarly journals The Schizosaccharomyces pombe cho1+ Gene Encodes a Phospholipid Methyltransferase

Genetics ◽  
1998 ◽  
Vol 150 (2) ◽  
pp. 553-562
Author(s):  
Margaret I Kanipes ◽  
John E Hill ◽  
Susan A Henry
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Sequence Analysis ◽  
Schizosaccharomyces Pombe ◽  
Gene Disruption ◽  
Structure And Function ◽  
Biosynthetic Enzyme ◽  
Gene Encoding ◽  
Complementation Groups ◽  
Eukaryotic Organisms ◽  
And Function

Abstract The isolation of mutants of Schizosaccharomyces pombe defective in the synthesis of phosphatidylcholine via the methylation of phosphatidylethanolamine is reported. These mutants are choline auxotrophs and fall into two unlinked complementation groups, cho1 and cho2. We also report the analysis of the cho1+ gene, the first structural gene encoding a phospholipid biosynthetic enzyme from S. pombe to be cloned and characterized. The cho1+ gene disruption mutant (cho1Δ) is viable if choline is supplied and resembles the cho1 mutants isolated after mutagenesis. Sequence analysis of the cho1+ gene indicates that it encodes a protein closely related to phospholipid methyltransferases from Saccharomyces cerevisiae and rat. Phospholipid methyltransferases encoded by a rat liver cDNA and the S. cerevisiae OPI3 gene are both able to complement the choline auxotrophy of the S. pombe cho1 mutants. These results suggest that both the structure and function of the phospholipid N-methyltransferases are broadly conserved among eukaryotic organisms.

scholarly journals The structure and function of centriolar rootlets

2021 ◽  
Vol 134 (16) ◽  
Author(s):  
Robert Mahen
Keyword(s):  
Cellular Function ◽  
Structure And Function ◽  
Cellular Systems ◽  
Macromolecular Assemblies ◽  
Cellular Processes ◽  
Holistic Understanding ◽  
Eukaryotic Organisms ◽  
And Function ◽  
Knockout Animals

ABSTRACT To gain a holistic understanding of cellular function, we must understand not just the role of individual organelles, but also how multiple macromolecular assemblies function collectively. Centrioles produce fundamental cellular processes through their ability to organise cytoskeletal fibres. In addition to nucleating microtubules, centrioles form lesser-known polymers, termed rootlets. Rootlets were identified over a 100 years ago and have been documented morphologically since by electron microscopy in different eukaryotic organisms. Rootlet-knockout animals have been created in various systems, providing insight into their physiological functions. However, the precise structure and function of rootlets is still enigmatic. Here, I consider common themes of rootlet function and assembly across diverse cellular systems. I suggest that the capability of rootlets to form physical links from centrioles to other cellular structures is a general principle unifying their functions in diverse cells and serves as an example of how cellular function arises from collective organellar activity.

scholarly journals Renal ischemia alters expression of mitochondria-related genes and impairs mitochondrial structure and function in swine scattered tubular-like cells

2020 ◽  
Vol 319 (1) ◽  
pp. F19-F28 ◽  
Author(s):  
Rahele A. Farahani ◽  
Xiang-Yang Zhu ◽  
Hui Tang ◽  
Kyra L. Jordan ◽  
Lilach O. Lerman ◽  
...  
Keyword(s):  
Gene Expression ◽  
Structural Damage ◽  
Nuclear Dna ◽  
Mitochondrial Genes ◽  
Structure And Function ◽  
Mitochondrial Damage ◽  
Renal Ischemia ◽  
Gene Gain ◽  
Mitochondrial Structure ◽  
And Function

Scattered tubular-like cells (STCs) are dedifferentiated surviving tubular epithelial cells that repair neighboring injured cells. Experimental renal artery stenosis (RAS) impairs STC reparative potency by inducing mitochondrial injury, but the exact mechanisms of mitochondrial damage remain unknown. We hypothesized that RAS alters expression of mitochondria-related genes, contributing to mitochondrial structural damage and dysfunction in swine STCs. CD24+/CD133+ STCs were isolated from pig kidneys after 10 wk of RAS or sham ( n = 3 each). mRNA sequencing was performed, and nuclear DNA (nDNA)-encoded mitochondrial genes and mitochondrial DNA (mtDNA)-encoded genes were identified. Mitochondrial structure, ATP generation, biogenesis, and expression of mitochondria-associated microRNAs were also assessed. There were 96 nDNA-encoded mitochondrial genes upregulated and 12 mtDNA-encoded genes downregulated in RAS-STCs versus normal STCs. Functional analysis revealed that nDNA-encoded and mtDNA-encoded differentially expressed genes were primarily implicated in mitochondrial respiration and ATP synthesis. Mitochondria from RAS STCs were swollen and showed cristae remodeling and loss and decreased ATP production. Immunoreactivity of the mitochondrial biogenesis marker peroxisome proliferator-activated receptor-γ coactivator (PGC)-1α and expression of the mitochondria-associated microRNAs miR-15a, miR-181a, miR-196a, and miR-296-3p, which target several mtDNA genes, were higher in RAS-STCs compared with normal STCs, suggesting a potential modulation of mitochondria-related gene expression. These results demonstrate that RAS induces an imbalance in mtDNA- and nDNA-mitochondrial gene expression, impairing mitochondrial structure and function in swine STCs. These observations support development of gene gain- and loss-of-function strategies to ameliorate mitochondrial damage and preserve the reparative potency of STCs in patients with renal ischemia.

Chemical tools for interrogating inositol pyrophosphate structure and function

2016 ◽  
Vol 45 (22) ◽  
pp. 6311-6326 ◽  
Author(s):  
Nathaniel W. Brown ◽  
Alan M. Marmelstein ◽  
Dorothea Fiedler
Keyword(s):  
Structure And Function ◽  
Intracellular Metabolites ◽  
Inositol Pyrophosphate ◽  
Inositol Pyrophosphates ◽  
Chemical Tools ◽  
Eukaryotic Organisms ◽  
And Function ◽  
Analytical Tools

New chemical and analytical tools have been developed to study the diverse functions of the inositol pyrophosphates, a unique group of densely phosphorylated intracellular metabolites found in a wide variety of eukaryotic organisms.

Assembly of adenovirus-specific nuclear inclusions in lytically infected HeLa cells: an ultrastructural and cytochemical study

1993 ◽  
Vol 71 (9-10) ◽  
pp. 475-487 ◽  
Author(s):  
Nathalie Chaly ◽  
Xia Chen
Keyword(s):  
Nuclear Dna ◽  
Chromatin Condensation ◽  
Structure And Function ◽  
Nuclear Inclusions ◽  
Dna Viruses ◽  
Cytochemical Study ◽  
Nuclear Ultrastructure ◽  
Interchromatin Granule ◽  
Nucleolar Volume ◽  
And Function

Adenoviruses (Ads) are nuclear DNA viruses that remodel host nuclear structure and function and induce formation of a variety of nuclear inclusions within which Ad DNA is replicated and transcribed. In this study, we have examined inclusion assembly by electron microscopy of samples stained conventionally or with bismuth to detect phosphoproteins. Small dense fibrillar bodies (DFBs) appeared very early associated with interchromatin granule (ICG) clusters. Somewhat later, similar DFBs lay near amorphous, loosely fibrillar structures that were moderately electron dense and showed little bismuth deposition. These clear fibrillar bodies (CFBs) enlarged and DFBs became embedded in their surface. At later stages, CFBs and DFBs were again dissociated. DFBs seen very early were poor in phosphoproteins, but later DFBs, whether embedded in the CFBs or lying near them, were intensely bismuth stained. DFBs and CFBs were less prominent once assembled virions were seen. At this late stage, virions were generally associated with moderately dense, slightly bismuth positive, irregularly shaped fibrillar inclusions that have previously been identified as viral genome storage sites. In addition, very dense fibrillar bodies, consisting usually of an electron-dense fibrillar shell and a less dense fibrogranular core, were observed at all but the earliest stages of infection, often at some distance from CFBs. There was also a major reorganization of host components during infection, including chromatin condensation, reduction of nucleolar volume and aggregation of the fibrillar regions at the nucleolar surface, and increased prominence of ICG clusters. A model is proposed for the assembly of Ad replication factories.Key words: adenovirus, lytic infection, replication factories, nuclear ultrastructure, cytochemistry.

scholarly journals Structure and function of RNA elements present in enteroviral genomes

2017 ◽  
Vol 63 (4) ◽  
Author(s):  
Mariola Dutkiewicz ◽  
Aleksandra Stachowiak ◽  
Agata Swiatkowska ◽  
Jerzy Ciesiołka
Keyword(s):  
Regulatory Elements ◽  
Structure And Function ◽  
Host Cells ◽  
Rna Structures ◽  
Coding Region ◽  
Protein Coding ◽  
Reading Frame ◽  
Noncoding Regions ◽  
Long Time ◽  
And Function

Enteroviruses are small RNA(+) viruses that encode one open reading frame flanked by two extensive noncoding regions carrying structural RNA regulatory elements that control replication and translation processes. For a long time the central, coding region was thought to remain single-stranded and its only function was supposed to be as the template for polyprotein synthesis. It turned out, however, that the protein coding region also encodes important RNA structures crucial for the viral life cycle and virus persistence in host cells. This review considers the RNA structures in enteroviral genomes identified and characterized to date.

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