scholarly journals Mitochondrial pseudogenes in insect DNA barcoding: differing points of view on the same issue

2012 ◽  
Vol 12 (3) ◽  
pp. 301-308 ◽  
Author(s):  
Luis Anderson Ribeiro Leite
Keyword(s):  
Mitochondrial Dna ◽  
Dna Barcoding ◽  
Nuclear Genome ◽  
Short Sequence ◽  
Dna Barcodes ◽  
Molecular Tools ◽  
Points Of View ◽  
Living Organisms ◽  
As If

Molecular tools have been used in taxonomy for the purpose of identification and classification of living organisms. Among these, a short sequence of the mitochondrial DNA, popularly known as DNA barcoding, has become very popular. However, the usefulness and dependability of DNA barcodes have been recently questioned because mitochondrial pseudogenes, non-functional copies of the mitochondrial DNA incorporated into the nuclear genome, have been found in various taxa. When these paralogous sequences are amplified together with the mitochondrial DNA, they may go unnoticed and end up being analyzed as if they were orthologous sequences. In this contribution the different points of view regarding the implications of mitochondrial pseudogenes for entomology are reviewed and discussed. A discussion of the problem from a historical and conceptual perspective is presented as well as a discussion of strategies to keep these nuclear mtDNA copies out of sequence analyzes.

scholarly journals Imagining Sisyphus happy: DNA barcoding and the unnamed majority

2016 ◽  
Vol 371 (1702) ◽  
pp. 20150329 ◽  
Author(s):  
Mark Blaxter
Keyword(s):  
Dna Barcoding ◽  
Time Frame ◽  
Morphological Identification ◽  
Dna Barcodes ◽  
Species Definition ◽  
Operational Taxonomic Units ◽  
The Earth ◽  
Biodiversity Science ◽  
Reasonable Time Frame

The vast majority of life on the Earth is physically small, and is classifiable as micro- or meiobiota. These organisms are numerically dominant and it is likely that they are also abundantly speciose. By contrast, the vast majority of taxonomic effort has been expended on ‘charismatic megabionts’: larger organisms where a wealth of morphology has facilitated Linnaean species definition. The hugely successful Linnaean project is unlikely to be extensible to the totality of approximately 10 million species in a reasonable time frame and thus alternative toolkits and methodologies need to be developed. One such toolkit is DNA barcoding, particularly in its metabarcoding or metagenetics mode, where organisms are identified purely by the presence of a diagnostic DNA sequence in samples that are not processed for morphological identification. Building on secure Linnaean foundations, classification of unknown (and unseen) organisms to molecular operational taxonomic units (MOTUs) and deployment of these MOTUs in biodiversity science promises a rewarding resolution to the Sisyphean task of naming all the world's species. This article is part of the themed issue ‘From DNA barcodes to biomes’.

scholarly journals Differential Transfer and Dissemination of Hypovirus and Nuclear and Mitochondrial Genomes of a Hypovirus-Infected Cryphonectria parasitica Strain after Introduction into a Natural Population

2003 ◽  
Vol 69 (7) ◽  
pp. 3767-3771 ◽  
Author(s):  
Patrik J. Hoegger ◽  
Ursula Heiniger ◽  
Ottmar Holdenrieder ◽  
Daniel Rigling
Keyword(s):  
Biological Control ◽  
Mitochondrial Dna ◽  
Nuclear Genome ◽  
Cryphonectria Parasitica ◽  
Plant Diseases ◽  
Mitochondrial Genomes ◽  
Chestnut Blight ◽  
Fungal Host ◽  
Chestnut Blight Fungus ◽  
Living Organisms

ABSTRACT Biological control of plant diseases generally requires release of living organisms into the environment. Cryphonectria hypoviruses function as biological control agents for the chestnut blight fungus, Cryphonectria parasitica, and hypovirus-infected C. parasitica strains can be used to treat infected trees. We used naturally occurring molecular marker polymorphisms to examine the persistence and dissemination of the three genomes of a hypovirus-infected C. parasitica strain, namely, the double-stranded RNA genome of Cryphonectria hypovirus 1 (CHV1) and the nuclear and mitochondrial genomes of its fungal host. The hypovirus-infected strain was experimentally introduced into a blight-infested chestnut coppice forest by treating 73 of 246 chestnut blight cankers. Two years after introduction, the hypovirus had disseminated to 36% of the untreated cankers and to 35% of the newly established cankers. Spread of the hypovirus was more frequent within treated sprout clusters than between sprout clusters. Mitochondrial DNA of the introduced fungus also was transferred into the resident C. parasitica population. Concomitant transfer of both the introduced hypovirus and mitochondrial DNA was detected in almost one-half of the treated cankers analyzed. The introduced mitochondrial DNA haplotype also was found in three resident isolates from newly established cankers. The nuclear genome of the introduced strain persisted in the treated cankers but did not spread beyond them.

Validation of Heterocerus heydeni Kuwert, 1890 based on morphology and DNA barcoding, with notes on the problems of classification of the Heteroceridae (Coleoptera)

Zootaxa ◽  
2019 ◽  
Vol 4614 (1) ◽  
pp. 160
Author(s):  
STANISLAV V. LITOVKIN ◽  
ALEXEY S. SAZHNEV ◽  
FEDOR JR ČIAMPOR
Keyword(s):  
Central Asia ◽  
Dna Barcoding ◽  
Morphological Characters ◽  
European Part ◽  
Junior Synonym ◽  
Data Systems ◽  
Dna Barcodes ◽  
Life Data ◽  
European Part Of Russia

New taxonomic data on mud-loving beetles are provided based on morphological characters and DNA barcoding. Heterocerus heydeni Kuwert, 1890 was previously considered a junior synonym of H. flexuosus Stephens, 1828, but we support the validity of the species and restore the name. H. heydeni is redescribed, based on material from Central Asia and European part of Russia. Specimens of H. hauseri Kuwert, 1893 were also studied, suggesting it as a possible junior synonym of H. heydeni. We provide new DNA barcodes for H. flexuosus and Augyles cf. flavidus and comment on Heterocerus barcode data published in Barcode Of Life Data Systems (BOLD). 

scholarly journals Reference DNA barcodes and other mitochondrial markers for identifying Caribbean Octocorals

2019 ◽  
Vol 7 ◽  
Author(s):  
Jaime Morín ◽  
Dagoberto Venera-Pontón ◽  
Amy Driskell ◽  
Juan Sánchez ◽  
Howard Lasker ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Cytochrome Oxidase ◽  
Dna Barcoding ◽  
Ribosomal Rna ◽  
Nadh Dehydrogenase ◽  
Dna Barcodes ◽  
Mitochondrial Markers ◽  
C Subunit ◽  
The Caribbean ◽  
Mixed Samples

DNA barcoding is a useful tool for documenting the diversity of metazoans. The most commonly used barcode markers, 16S and COI, are not considered suitable for species identification within some "basal" phyla of metazoans. Nevertheless metabarcoding studies of bulk mixed samples commonly use these markers and may obtain sequences for "basal" phyla. We sequenced mitochondrial DNA fragments of cytochrome oxidase c subunit I (COI), 16S ribosomal RNA (16S), NADH dehydrogenase subunits 2 (16S-ND2), 6 (ND6-ND3) and 4L (ND4L-MSH) for 27 species of Caribbean octocorals to create a reference barcode dataset and to compare the utility of COI and 16S to other markers more typically used for octocorals. The most common genera (Erythropodium, Ellisella, Briareum, Plexaurella, Muriceopsis and Pterogorgia) were effectively distinguished by small differences (5 or more substitutions or indels) in COI and 16S sequences. Gorgonia and Antillogorgia were effectively distinguished from each other by unique haplotypes, but the small genetic differences make distance approaches ineffective for these taxa. Plexaura, Pseudoplexaura and Eunicea were indistinguishable from each other but were generally effectively distinguished from other genera, further supporting the idea that these genera have undergone a rapid endemic radiation in the Caribbean.

Development of a mito-CRISPR system for generating mitochondrial DNA-deleted strain in Saccharomyces cerevisiae

2020 ◽  
Vol 85 (4) ◽  
pp. 895-901
Author(s):  
Takamitsu Amai ◽  
Tomoka Tsuji ◽  
Mitsuyoshi Ueda ◽  
Kouichi Kuroda
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mitochondrial Dna ◽  
Ethidium Bromide ◽  
Nuclear Genome ◽  
Target Sequence ◽  
Guide Rna ◽  
Crispr System ◽  
Mitochondrial Target ◽  
Gene Treatment ◽  
Mtdna Deletion

ABSTRACT Mitochondrial dysfunction can occur in a variety of ways, most often due to the deletion or mutation of mitochondrial DNA (mtDNA). The easy generation of yeasts with mtDNA deletion is attractive for analyzing the functions of the mtDNA gene. Treatment of yeasts with ethidium bromide is a well-known method for generating ρ° cells with complete deletion of mtDNA from Saccharomyces cerevisiae. However, the mutagenic effects of ethidium bromide on the nuclear genome cannot be excluded. In this study, we developed a “mito-CRISPR system” that specifically generates ρ° cells of yeasts. This system enabled the specific cleavage of mtDNA by introducing Cas9 fused with the mitochondrial target sequence at the N-terminus and guide RNA into mitochondria, resulting in the specific generation of ρ° cells in yeasts. The mito-CRISPR system provides a concise technology for deleting mtDNA in yeasts.

scholarly journals Mitochondrial DNA Methylation and Human Diseases

2021 ◽  
Vol 22 (9) ◽  
pp. 4594
Author(s):  
Andrea Stoccoro ◽  
Fabio Coppedè
Keyword(s):  
Dna Methylation ◽  
Mitochondrial Dna ◽  
Mitochondrial Genome ◽  
Nuclear Dna ◽  
Epigenetic Modification ◽  
Nuclear Genome ◽  
Epigenetic Modifications ◽  
Human Diseases ◽  
Loop Region ◽  
D Loop

Epigenetic modifications of the nuclear genome, including DNA methylation, histone modifications and non-coding RNA post-transcriptional regulation, are increasingly being involved in the pathogenesis of several human diseases. Recent evidence suggests that also epigenetic modifications of the mitochondrial genome could contribute to the etiology of human diseases. In particular, altered methylation and hydroxymethylation levels of mitochondrial DNA (mtDNA) have been found in animal models and in human tissues from patients affected by cancer, obesity, diabetes and cardiovascular and neurodegenerative diseases. Moreover, environmental factors, as well as nuclear DNA genetic variants, have been found to impair mtDNA methylation patterns. Some authors failed to find DNA methylation marks in the mitochondrial genome, suggesting that it is unlikely that this epigenetic modification plays any role in the control of the mitochondrial function. On the other hand, several other studies successfully identified the presence of mtDNA methylation, particularly in the mitochondrial displacement loop (D-loop) region, relating it to changes in both mtDNA gene transcription and mitochondrial replication. Overall, investigations performed until now suggest that methylation and hydroxymethylation marks are present in the mtDNA genome, albeit at lower levels compared to those detectable in nuclear DNA, potentially contributing to the mitochondria impairment underlying several human diseases.

HaploGrep: a fast and reliable algorithm for automatic classification of mitochondrial DNA haplogroups

2010 ◽  
Vol 32 (1) ◽  
pp. 25-32 ◽  
Author(s):  
Anita Kloss-Brandstätter ◽  
Dominic Pacher ◽  
Sebastian Schönherr ◽  
Hansi Weissensteiner ◽  
Robert Binna ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Automatic Classification

scholarly journals Benchmarking DNA barcodes: an assessment using available primate sequences

Genome ◽  
2006 ◽  
Vol 49 (7) ◽  
pp. 851-854 ◽  
Author(s):  
Mehrdad Hajibabaei ◽  
Gregory AC Singer ◽  
Donal A Hickey
Keyword(s):  
New Species ◽  
Cryptic Species ◽  
Dna Barcoding ◽  
Species Identification ◽  
Dna Sequences ◽  
Phylogenetic Relationships ◽  
Primate Species ◽  
Dna Barcodes ◽  
Global Biodiversity ◽  
Efficient Sequence

DNA barcoding has been recently promoted as a method for both assigning specimens to known species and for discovering new and cryptic species. Here we test both the potential and the limitations of DNA barcodes by analysing a group of well-studied organisms—the primates. Our results show that DNA barcodes provide enough information to efficiently identify and delineate primate species, but that they cannot reliably uncover many of the deeper phylogenetic relationships. Our conclusion is that these short DNA sequences do not contain enough information to build reliable molecular phylogenies or define new species, but that they can provide efficient sequence tags for assigning unknown specimens to known species. As such, DNA barcoding provides enormous potential for use in global biodiversity studies.Key words: DNA barcoding, species identification, primate, biodiversity.

Natural history of ABC systems: not only transporters

2011 ◽  
Vol 50 ◽  
pp. 19-42 ◽  
Author(s):  
Elie Dassa
Keyword(s):  
Common Ancestor ◽  
Three Dimensional ◽  
Last Common Ancestor ◽  
Abc Proteins ◽  
Hypothetical Scenario ◽  
History Of ◽  
Phylogenetic Perspective ◽  
Living Organisms

In recent years, our understanding of the functioning of ABC (ATP-binding cassette) systems has been boosted by the combination of biochemical and structural approaches. However, the origin and the distribution of ABC proteins among living organisms are difficult to understand in a phylogenetic perspective, because it is hard to discriminate orthology and paralogy, due to the existence of horizontal gene transfer. In this chapter, I present an update of the classification of ABC systems and discuss a hypothetical scenario of their evolution. The hypothetical presence of ABC ATPases in the last common ancestor of modern organisms is discussed, as well as the additional possibility that ABC systems might have been transmitted to eukaryotes, after the two endosymbiosis events that led to the constitution of eukaryotic organelles. I update the functional information of selected ABC systems and introduce new families of ABC proteins that have been included recently into this vast superfamily, thanks to the availability of high-resolution three-dimensional structures.

scholarly journals Evidence for non-neutrality of mitochondrial DNA haplotypes in Drosophila pseudoobscura.

Genetics ◽  
1988 ◽  
Vol 120 (2) ◽  
pp. 485-494
Author(s):  
A F MacRae ◽  
W W Anderson
Keyword(s):  
Mitochondrial Dna ◽  
Nuclear Genome ◽  
Drosophila Pseudoobscura ◽  
Initial Population ◽  
Mitochondrial Haplotypes ◽  
Mtdna Haplotypes ◽  
Selective Neutrality ◽  
Frequency Changes ◽  
Apparent Equilibrium ◽  
Neutral Markers

Abstract Mitochondrial DNA (mtDNA) haplotypes usually are assumed to be neutral, unselected markers of evolving female lineages. This assumption was tested by monitoring haplotype frequencies in 12 experimental populations of Drosophila pseudoobscura which were polymorphic for mtDNA haplotypes. Populations were maintained for at least 10 generations, and in one case for 32 generations, while tests of mtDNA selective neutrality were conducted. In an initial population, formed from a mixture of two strains with different mitochondrial haplotypes, the frequency of the Bogota haplotype increased 46% in 3 generations, reaching an apparent equilibrium frequency of 82% after 32 generations. Perturbation of this equilibrium by addition of the less common haplotype resulted in a rapid, dramatic increase in frequency of the second haplotype, and a return to essentially the same equilibrium frequency as before perturbation. This behavior is not consistent with mtDNA neutrality, nor is the equilibrium consistent with a simple model of constant selection on the haploid mtDNAs. Replicate cage experiments with mtDNA haplotypes did not always generate the same result as the initial cage. Several lines of evidence, including manipulations of the nuclear genome, support the idea that both nuclear and mitochondrial genomes are involved in the dramatic mtDNA frequency changes. In another experiment, strong female viability selection was implicated via mtDNA frequency changes. Although the causes of the dramatic mtDNA frequency changes in our populations are not obvious, it is clear that Drosophila mitochondrial haplotypes are not always simply neutral markers. Our findings are relevant to the introduction of a novel mtDNA variant from one species or one population into another. Such introductions could be strongly favored by selection, even if it is sporadic.

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