scholarly journals Mitochondrial DNA: a blind spot in neuroepigenetics

2012 ◽  
Vol 3 (2) ◽  
pp. 107-115 ◽  
Author(s):  
Hari Manev ◽  
Svetlana Dzitoyeva ◽  
Hu Chen
Keyword(s):  
Mitochondrial Dna ◽  
Nuclear Dna ◽  
Blind Spot ◽  
Dna Methyltransferases ◽  
Molecular Neuroscience ◽  
Dna Modifications ◽  
System Physiology ◽  
Near Future ◽  
First Time ◽  
The Brain

AbstractNeuroepigenetics, which includes nuclear DNA modifications, such as 5-methylcytosine and 5-hydroxymethylcytosine and modifications of nuclear proteins, such as histones, is emerging as the leading field in molecular neuroscience. Historically, a functional role for epigenetic mechanisms, including in neuroepigenetics, has been sought in the area of the regulation of nuclear transcription. However, one important compartment of mammalian cell DNA, different from nuclear DNA but equally important for physiological and pathological processes (including in the brain), mitochondrial DNA has for the most part not had a systematic epigenetic characterization. The importance of mitochondria and mitochondrial DNA (particularly its mutations) in central nervous system physiology and pathology has long been recognized. Only recently have the mechanisms of mitochondrial DNA methylation and hydroxymethylation, including the discovery of mitochondrial DNA-methyltransferases and the presence and functionality of 5-methylcytosine and 5-hydroxymethylcytosine in mitochondrial DNA (e.g., in modifying the transcription of mitochondrial genome), been unequivocally recognized as a part of mammalian mitochondrial physiology. Here, we summarize for the first time evidence supporting the existence of these mechanisms and propose the term ‘mitochondrial epigenetics’ to be used when referring to them. Currently, neuroepigenetics does not include mitochondrial epigenetics – a gap that we expect to close in the near future.

Mitochondrial DNA and the evolutionary genetics of higher animals

1986 ◽  
Vol 312 (1154) ◽  
pp. 325-342 ◽  
Keyword(s):  
Mitochondrial Dna ◽  
Population Genetic ◽  
Life Histories ◽  
Nuclear Dna ◽  
Molecular Level ◽  
Evolutionary Genetics ◽  
Genetic System ◽  
Phylogenetic Status ◽  
First Time ◽  
Genetic Characters

Mitochondrial DNA (mtDNA) in higher animals is rapidly becoming a well characterized genetic system at the molecular level. In this paper, I shift the focus to consider questions in organismal evolution that can be addressed by mtDNA assay. For the first time, it is possible to estimate empirically matriarchal phylogeny; to determine directionality in crosses producing hybrids; and to study the population genetic consequences of varying female demographies and life histories. The data obtainable from mtDNA may be especially well suited for studies of population genetic structure, dispersal, and historical zoogeography. The female-mediated, clonal transmission of mtDNA is also stimulating new ways of thinking about times to common ancestry of asexual lineages within otherwise sexually reproducing populations; about the possible relevance of mtDNA-nuclear DNA interactions to reproductive isolation; and about the very meaning of the phylogenetic status of related species with respect to particular kinds of genetic characters. These and other topics are reviewed.

scholarly journals Genetic research of anadromous herring in Volga-Caspian fishery basin

2019 ◽  
Vol 2019 (4) ◽  
pp. 116-123
Author(s):  
Ekaterina Grigorievna Makarova ◽  
Natalia Victorovna Kozlova ◽  
Margarita Armenovna Baregamyan ◽  
Tatyana Victorovna Voinova
Keyword(s):  
Mitochondrial Dna ◽  
Cytochrome B ◽  
Nuclear Dna ◽  
Molecular Genetic ◽  
Genetic Research ◽  
Nucleotide Substitutions ◽  
Polymorphic Loci ◽  
Low Level ◽  
Dna Microsatellite ◽  
First Time

For the first time, a study of genetic variability of Caspian anadromous herring was carried out using molecular genetic methods. Sequencing of the cytochrome B site of mitochondrial DNA allowed to identify 7 haplotypes. The most massive haplotype was Hap_Alosa1 noted in 29 herring individuals. Five minor haplotypes were detected in few fish individuals. In the marine period of life in fish caught in the Northern Caspian there were noted rare haplotypes Hap_Alosa6 and Hap_Alosa7. In the river period of life in the Volga herring there was observed Hap_Alosa5. The revealed polymorphism of haplotypes was represented by single nucleotide substitutions. The genetic analysis of migratory herring does not give grounds for isolating the studied fish into separate groups. The marked low level of nucleotide diversity of cytochrome B gene of mitochondrial DNA of the anodromous herring indicates a significant genetic homogeneity of the species within the studied range. The results of analysis of nuclear DNA microsatellite loci showed that only three of the six sites of the studied gene were polymorphic. In individuals caught in the river period of life, only Af20 (out of the 6 loci studied) was polymorphic and was characterized by 4 alleles. In a sample of herring from the Northern Caspian, 3 polymorphic loci (Aa16, Af6 and Af20) were observed, in which 2 alleles were recorded. The observed heterozygosity varied from 0.313 to 0.667 exceeding the level of expected heterozygosity. In polymorphic loci a deficit of heterozygotes was not noted. The results obtained in this study indicate a low level of genetic variation of anadromous herring.

Dwindling status of Epimedium Elatum (Morren & Decne) and its geographical distribution in Kashmir Himalaya, India

2018 ◽  
pp. 47-52
Keyword(s):  
Medicinal Plant ◽  
Biological Activities ◽  
Conservation Status ◽  
Natural Populations ◽  
Culture Techniques ◽  
Kashmir Himalayas ◽  
Near Future ◽  
First Time ◽  
Tissue Culture Techniques

Epimedium elatum (Morren & Decne) of family Berberidaceace is a rare perennial medicinal plant, endemic to high altitude forests of Northwestern Himalayas in India. Ethnobotanically, it has been used as an ingredient for treatment of bone-joint disorders, impotence and kidney disorders in Kashmir Himalayas. Phytochemically, it is rich in Epimedin ABC and Icariin; all of these have been demonstrated to possess remarkable biological activities like PDE-5 inhibition (treatment of erectile dysfunction), anticancer, antiosteoporosis antioxidant and antiviral properties. The present investigation reports its traditional usage, comprehensive distribution and conservation status from twenty ecogeographical regions in Kashmir Himalayas, India. The species was reported from Gurez valley for the first time. Numerous threats like excessive grazing, deforestration, habitat fragmentation, tourism encroachment, landslides and excessive exploitation have decreased its natural populations in most of the surveyed habitats. Consequently, its existence may become threatened in near future if timely conservation steps are not taken immediately by concerned stakeholders involved in medicinal plant research. Moreover, use of plant tissue culture techniques is recommended for development of its in vitro propagation protocols. Therefore, introduction of this medicinal plant in botanical gardens, protected sites and development of monitoring programmes are needed for its immediate conservation in Northwestern Himalayas, India.

Organic Reactivity Control by Means of Neighboring Groups and Organometallics. A Personal Account

1994 ◽  
Vol 59 (1) ◽  
pp. 1-74 ◽  
Author(s):  
Pavel Kočovský
Keyword(s):  
Transition Metals ◽  
Cyclopropane Ring ◽  
Allylic Substitutions ◽  
Recent Developments ◽  
Cardioactive Drug ◽  
Novel Method ◽  
Metal Catalyzed ◽  
Electrophilic Additions ◽  
Near Future ◽  
First Time

This review summarizes the main topics of our research and covers the period of the last 15 years. The prime interest is focused on various ways of controlling the regio- and stereoselectivity of selected organic reactions, in particular electrophilic additions, cleavage of cyclopropane rings, and allylic substitutions by means of neighboring groups and/or transition and non-transition metals. In the first part, the factors governing the course of electrophilic additions are assessed, culminating in the formulation of selection rules for the reactivity of cyclohexene systems, and in a concise synthesis of the natural cardioactive drug, strophanthidin. These studies also contribute to a better understanding of the mechanisms of electrophilic additions. The second part describes recent developments in the stereo- and regiocontrolled cleavage of cyclopropane rings by non-transition metals (Tl and Hg), and the reactivity and transmetalation (with Pd) of the primary products. This methodology has resulted in novel routes to unique polycyclic structures, and will have synthetic applications in the near future. Evidence for the stereospecific "corner" cleavage of the cyclopropane ring has been provided for the first time for Tl and later for Hg. The third part deals with transition metal-catalyzed allylic substitution. Evidence for a new "syn" mechanism for the formation of the intermediate (π-allyl)palladium complex has been provided, which runs counter to the generally accepted "anti" mechanism. A novel method for a Pd-catalyzed allylic oxidation has been developed and employed in the synthesis of natural sesquiterpenes. The increasing importance of transition and non-transition metals for synthetic organic chemistry is demonstrated by their unique reactivity in a number of the papers included in this review.

scholarly journals Cytosolic Ribosomal Mutations That Abolish Accumulation of Circular Intron in the Mitochondria Without Preventing Senescence of Podospora anserina

Genetics ◽  
1997 ◽  
Vol 145 (3) ◽  
pp. 697-705 ◽  
Author(s):  
Philippe Silar ◽  
France Koll ◽  
Michèle Rossignol
Keyword(s):  
Mitochondrial Dna ◽  
Ribosomal Proteins ◽  
Podospora Anserina ◽  
Cox1 Gene ◽  
Accuracy Control ◽  
Additional Function ◽  
Mutant Proteins ◽  
Double Stranded Dna ◽  
Dna Modifications

The filamentous fungus Podospora anserina presents a degeneration syndrome called Senescence associated with mitochondrial DNA modifications. We show that mutations affecting the two different and interacting cytosolic ribosomal proteins (S7 and S19) systematically and specifically prevent the accumulation of senDNAα (a circular double-stranded DNA plasmid derived from the first intron of the mitochondrial cox1 gene or intron α) without abolishing Senescence nor affecting the accumulation of other usually observed mitochondrial DNA rearrangements. One of the mutant proteins is homologous to the Escherichia coli S4 and Saccharomyces cerevisiae S13 ribosomal proteins, known to be involved in accuracy control of cytosolic translation. The lack of accumulation of senDNAα seems to result from a nontrivial ribosomal alteration unrelated to accuracy control, indicating that S7 and S19 proteins have an additional function. The results strongly suggest that modified expression of nucleus-encoded proteins contributes to Senescence in P. anserina. These data do not fit well with some current models, which propose that intron α plays the role of the cytoplasmic and infectious Determinant of Senescence that was defined in early studies.

scholarly journals EU Operational Powers and Legal Protection: A Legal Theory Perspective on the Operational Powers of the European Border and Coast Guard

2021 ◽  
Vol 22 (4) ◽  
pp. 625-649
Author(s):  
Bas Schotel
Keyword(s):  
Legal Theory ◽  
Legal Protection ◽  
European Parliament ◽  
Blind Spot ◽  
Public Law ◽  
Coast Guard ◽  
Public Power ◽  
Legal Constraints ◽  
First Time ◽  
The Eu

AbstractFor the first time in its history, the EU is in the process of acquiring significant and genuine permanent operational powers. A new Regulation on the European Border and Coast Guard provides Frontex with a permanent corps of 10,000 border guards—3,000 of which will be EU agents—its own equipment, and its own competences to intervene along the EU borders and beyond. The operational powers will allow the EU to directly and physically intervene in tangible reality.This Article argues that the conferral of operational powers on the EU poses a risk to individual legal protection. This is because once authorities have acquired operational powers of a certain extent and quality, they can afford to act against or without the law by simply overpowering or eluding the legal mechanisms that normally constrain the exercise of public power. So far, Members of the European Parliament and academics critical of Frontex and the new Regulation have overlooked this issue and concentrated exclusively on how to legally constrain the exercise of operational powers. This Article addresses this blind spot by examining whether and how public law should place legal constraints not only on the exercise but also on the build-up of operational powers.

scholarly journals The Role of Mitochondria in Carcinogenesis

2021 ◽  
Vol 22 (10) ◽  
pp. 5100
Author(s):  
Paulina Kozakiewicz ◽  
Ludmiła Grzybowska-Szatkowska ◽  
Marzanna Ciesielka ◽  
Jolanta Rzymowska
Keyword(s):  
Prostate Cancer ◽  
Mitochondrial Dna ◽  
Nuclear Dna ◽  
Dna Polymorphisms ◽  
Gene Encoding ◽  
Dna Mutations ◽  
Nadh Ubiquinone Oxidoreductase ◽  
Gene Coi ◽  
The Impact

The mitochondria are essential for normal cell functioning. Changes in mitochondrial DNA (mtDNA) may affect the occurrence of some chronic diseases and cancer. This process is complex and not entirely understood. The assignment to a particular mitochondrial haplogroup may be a factor that either contributes to cancer development or reduces its likelihood. Mutations in mtDNA occurring via an increase in reactive oxygen species may favour the occurrence of further changes both in mitochondrial and nuclear DNA. Mitochondrial DNA mutations in postmitotic cells are not inherited, but may play a role both in initiation and progression of cancer. One of the first discovered polymorphisms associated with cancer was in the gene NADH-ubiquinone oxidoreductase chain 3 (mt-ND3) and it was typical of haplogroup N. In prostate cancer, these mutations and polymorphisms involve a gene encoding subunit I of respiratory complex IV cytochrome c oxidase subunit 1 gene (COI). At present, a growing number of studies also address the impact of mtDNA polymorphisms on prognosis in cancer patients. Some of the mitochondrial DNA polymorphisms occur in both chronic disease and cancer, for instance polymorphism G5913A characteristic of prostate cancer and hypertension.

Evidence for genetic hybridization between Ixodes scapularis and Ixodes cookei

2017 ◽  
Vol 95 (8) ◽  
pp. 527-537 ◽  
Author(s):  
James W. Patterson ◽  
Anna M. Duncan ◽  
Kelsey C. McIntyre ◽  
Vett K. Lloyd
Keyword(s):  
Mitochondrial Dna ◽  
Genetic Analysis ◽  
New Brunswick ◽  
Nuclear Dna ◽  
Ixodes Scapularis ◽  
Companion Animals ◽  
Genetic Introgression ◽  
Eastern Canada ◽  
As Species ◽  
Intermediate Traits

Ixodes scapularis Say, 1821 (the black-legged tick) is becoming established in Canada. The northwards expansion of I. scapularis leads to contact between I. scapularis and Ixodes cookei Packard, 1869, a well-established tick species in Eastern Canada. Examination of I. cookei and I. scapularis collected from New Brunswick revealed ticks with ambiguous morphologies, with either a mixture or intermediate traits typical of I. scapularis and I. cookei, including in characteristics typically used as species identifiers. Genetic analysis to determine if these ticks represent hybrids revealed that four had I. cookei derived mitochondrial DNA but I. scapularis nuclear DNA. In one case, the nuclear sequence showed evidence of heterozygosity for I. scapularis and I. cookei sequences, whereas in the others, the nuclear DNA appeared to be entirely derived from I. scapularis. These data strongly suggest genetic hybridization between these two species. Ixodes cookei and hybrid ticks were readily collected from humans and companion animals and specimens infected with Borrelia burgdorferi Johnson et al., 1984, the causative agent of Lyme disease, were identified. These findings raise the issue of genetic introgression of I. scapularis genes into I. cookei and warrant reassessment of the capacity of I. cookei and I. cookei × I. scapularis hybrids to vector Borrelia infection.

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