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1.
Int J Mol Sci ; 22(12)2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-34203740

RESUMO

Heterosis utilization is very important in hybrid seed production. An AL-type cytoplasmic male sterile (CMS) line has been used in wheat-hybrid seed production, but its sterility mechanism has not been explored. In the present study, we sequenced and verified the candidate CMS gene in the AL-type sterile line (AL18A) and its maintainer line (AL18B). In the late uni-nucleate stage, the tapetum cells of AL18A showed delayed programmed cell death (PCD) and termination of microspore at the bi-nucleate stage. As compared to AL18B, the AL18A line produced 100% aborted pollens. The mitochondrial genomes of AL18A and AL18B were sequenced using the next generation sequencing such as Hiseq and PacBio. It was found that the mitochondrial genome of AL18A had 99% similarity with that of Triticum timopheevii, AL18B was identical to that of Triticum aestivum cv. Chinese Yumai. Based on transmembrane structure prediction, 12 orfs were selected as candidate CMS genes, including a previously suggested orf256. Only the lines harboring orf279 showed sterility in the transgenic Arabidopsis system, indicating that orf279 is the CMS gene in the AL-type wheat CMS lines. These results provide a theoretical basis and data support to further analyze the mechanism of AL-type cytoplasmic male sterility in wheat.


Assuntos
Genes de Plantas , Genoma Mitocondrial , Infertilidade das Plantas/genética , Triticum/genética , Arabidopsis/genética , Mapeamento Cromossômico , DNA Mitocondrial/genética , Estudos de Associação Genética , Proteínas de Plantas/química , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas , Pólen/genética
2.
Nat Protoc ; 16(7): 3625-3638, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34089018

RESUMO

The most common nonstandard nucleotides found in genomic DNA are ribonucleotides. Although ribonucleotides are frequently incorporated into DNA by replicative DNA polymerases, very little is known about the distribution and signatures of ribonucleotides incorporated into DNA. Recent advances in high-throughput ribonucleotide sequencing can capture the exact locations of ribonucleotides in genomic DNA. Ribose-Map is a user-friendly, standardized bioinformatics toolkit for the comprehensive analysis of ribonucleotide sequencing experiments. It allows researchers to map the locations of ribonucleotides in DNA to single-nucleotide resolution and identify biological signatures of ribonucleotide incorporation. In addition, it can be applied to data generated using any currently available high-throughput ribonucleotide sequencing technique, thus standardizing the analysis of ribonucleotide sequencing experiments and allowing direct comparisons of results. This protocol describes in detail how to use Ribose-Map to analyze ribonucleotide sequencing data, including preparing the reads for analysis, locating the genomic coordinates of ribonucleotides, exploring the genome-wide distribution of ribonucleotides, determining the nucleotide sequence context of ribonucleotides and identifying hotspots of ribonucleotide incorporation. Ribose-Map does not require background knowledge of ribonucleotide sequencing analysis and assumes only basic command-line skills. The protocol requires less than 3 h of computing time for most datasets and ~30 min of hands-on time. Ribose-Map is available at https://github.com/agombolay/ribose-map .


Assuntos
DNA Fúngico/genética , Genoma , Genômica/métodos , Ribonucleotídeos/genética , Ribose/metabolismo , Saccharomyces cerevisiae/genética , Sequência de Bases , Sequência Consenso/genética , DNA Mitocondrial/genética
3.
Methods Mol Biol ; 2276: 143-151, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34060038

RESUMO

Deoxynucleoside 5'-triphosphates (dNTPs) are the molecular building blocks for DNA synthesis, and their balanced concentration in the cell is fundamental for health. dNTP imbalance can lead to genomic instability and other metabolic disturbances, resulting in devastating mitochondrial diseases.The accurate and efficient measurement of dNTPs from different biological samples and cellular compartments is vital to understand the mechanisms behind these diseases and develop and scrutinize their possible treatments. This chapter describes an update on the most recent development of the traditional radiolabeled polymerase extension method and its adaptation for the measurement of whole-cell and mitochondrial dNTP pools from cultured cells and tissue samples. The solid-phase reaction setting enables an increase in efficiency, accuracy, and measurement scale.


Assuntos
Bioensaio/métodos , Fracionamento Celular/métodos , Células/metabolismo , Desoxirribonucleotídeos/metabolismo , Mitocôndrias/metabolismo , Animais , Células Cultivadas , DNA Mitocondrial/genética , DNA Mitocondrial/metabolismo , Humanos , Camundongos , Mitocôndrias/genética
4.
Zootaxa ; 4975(2): 369378, 2021 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-34186562

RESUMO

Oxynoemacheilus isauricus, new species, from the Lakes Beysehir and Sugla basins in Central Anatolia is distinguished from all other species of the O. angorae group by having a very slender caudal peduncle (its depth 2.22.6 times in its length). The new species is further distinguished by having a short head (head length 2124% SL), and a midlateral series of irregularly shaped blotches on the flank. Oxynoemacheilus isauricus is also distinguished by a minimum K2P sequence divergence of 7.5% and 8.0% in the mtDNA-COI barcode region from O. eregliensis and O. atili, its closest relatives.


Assuntos
Cipriniformes/classificação , Animais , Cipriniformes/anatomia & histologia , DNA Mitocondrial/genética , Lagos , Turquia
5.
Parasitol Res ; 120(7): 2505-2521, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34170388

RESUMO

The present paper describes Filisoma argusum n. sp. (Cavisomatidae), an acanthocephalan parasite infecting the intestine of the spotted scat, Scatophagus argus (Linnaeus, 1766), in the south-west coast of India. The prevalence is 18% (mean intensity: 1.61 and abundance: 1-4 worms/host). Filisoma argusum n. sp. is morphologically characterized by a creamy-white, cylindrical, elongate, aspinose, and robust trunk; a collar-like neck; and a cylindrical proboscis with 18-20 longitudinal rows of hooks, with 19-22 hooks/row. Proboscis receptacle long, double-walled. Lemnisci digitiform, equal, longer than proboscis receptacle. Females 79.14 ± 33.69 × 0.593 ± 0.19 mm; males 32.62 ± 2.98 × 0.46 ± 0.071 mm. Males with four cement glands; bulbous muscular copulatory bursa with six digitiform rays. SEM studies revealed smooth hooks, sensory pits, and epidermal micropores. Histopathological changes at the site of parasite attachment included inflammation, hemorrhage, sloughing of epithelium, and detachment of mucosal layer of the intestine. In molecular and phylogenetic analyses, the parasite occupied an independent position within the Cavisomatidae clade with high bootstrap values for both ITS1-5.8S and ITS2, and mt-CO1 regions. Considering the morphologic and morphometric differences with previously described species of Filisoma along with its phylogenetic positioning, the present acanthocephalan is treated as a new species and the name Filisoma argusum n. sp. is proposed.


Assuntos
Acantocéfalos/classificação , Peixes/parasitologia , Acantocéfalos/anatomia & histologia , Acantocéfalos/genética , Animais , DNA Mitocondrial/genética , DNA Ribossômico/genética , Feminino , Doenças dos Peixes/epidemiologia , Doenças dos Peixes/parasitologia , Helmintíase Animal/epidemiologia , Helmintíase Animal/parasitologia , Índia , Intestinos/parasitologia , Masculino , Filogenia , Especificidade da Espécie
6.
Zootaxa ; 4991(2): 295-317, 2021 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-34186846

RESUMO

We describe a new species of Anolis lizard from the Pacific slopes of the Andes of southwestern Ecuador at elevations between 3721,000 m. The new species belongs to the Dactyloa clade and may be distinguished from other Anolis by size, external anatomy, mitochondrial DNA divergence, and dewlap color. Based on phylogenetic analyses of mitochondrial and nuclear DNA sequence data, we found that the new species is sister to A. fraseri in a clade composed primarily of large Dactyloid species. The new species is known from a protected area in southern Ecuador, Buenaventura Reserve, which suggests that at least some its populations are well protected.


Assuntos
Lagartos/classificação , Animais , DNA Mitocondrial/genética , Equador , Lagartos/anatomia & histologia , Filogenia
7.
Methods Mol Biol ; 2277: 39-47, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34080143

RESUMO

Quantitative control of mitochondrial transfer is a promising approach for genetic manipulation of mitochondrial DNA (mtDNA) because it enables precise modulation of heteroplasmy. Furthermore, single mitochondrion transfer from a mtDNA mutation-accumulated cell to a mtDNA-less (ρ0) cell potentially achieves homoplasmy of mutated mtDNA. Here we describe the method for quantitative control of mitochondrial transfer including achieving single mitochondrion transfer between live single cells using a microfluidic device.


Assuntos
Fusão Celular , Técnicas Citológicas/métodos , Dispositivos Lab-On-A-Chip , Mitocôndrias/genética , Técnicas Citológicas/instrumentação , DNA Mitocondrial/genética , Desenho de Equipamento , Humanos , Mutação
8.
Methods Mol Biol ; 2277: 91-99, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34080146

RESUMO

Heteroplasmic mice represent a valuable tool to study the segregation of different mtDNA haplotypes (mtDNAs with differing alleles) in vivo against a defined nuclear background. We describe two methods for the creation of such models, differing in the resulting initial heteroplasmy levels: (a) transfer of ooplasm and (b) fusion of two blastomeres. These methods result in typical heteroplasmy of 5% and 50% donor mtDNA , respectively. The choice of method depends on the aim of the study. By means of breeding even 100% donor mtDNA can be reached within a few generations.


Assuntos
Citoplasma/transplante , DNA Mitocondrial/genética , Técnicas de Reprodução Assistida , Animais , Blastômeros , Fusão Celular/métodos , Citoplasma/genética , Técnicas de Cultura Embrionária , Feminino , Heteroplasmia , Camundongos , Gravidez
9.
Methods Mol Biol ; 2277: 125-132, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34080148

RESUMO

Mitochondrial dysfunction is regarded as a key factor involved in the pathogenesis of septic disorders, leading to a decline in energy supply. The influence of short- and medium-chain fatty acids (SCFA/MCFA) on mitochondrial respiration under inflammatory conditions has thus far not been investigated. In the following protocol we describe the assessment of mitochondrial respiration using high-resolution respirometry under inflammatory and baseline conditions. For this approach, human endothelial cells and monocytes were pretreated with TNF-α to mimic inflammation followed by incubation with SCFA/MCFA and then subjected to high-resolution respirometry. Mitochondrial DNA content was assessed by PCR .


Assuntos
Ácidos Graxos/farmacologia , Inflamação/metabolismo , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , DNA Mitocondrial/genética , Ácidos Graxos/química , Ácidos Graxos Voláteis/química , Ácidos Graxos Voláteis/farmacologia , Células Endoteliais da Veia Umbilical Humana , Humanos , Inflamação/patologia , Mitocôndrias/patologia , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , Monócitos/patologia , Fator de Necrose Tumoral alfa/farmacologia
10.
Methods Mol Biol ; 2277: 203-245, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34080154

RESUMO

Here we summarize our latest efforts to elucidate the role of mtDNA variants affecting the mitochondrial translation machinery, namely variants mapping to the mt-rRNA and mt-tRNA genes. Evidence is accumulating to suggest that the cellular response to interference with mitochondrial translation is different from that occurring as a result of mutations in genes encoding OXPHOS proteins. As a result, it appears safe to state that a complete view of mitochondrial disease will not be obtained until we understand the effect of mt-rRNA and mt-tRNA variants on mitochondrial protein synthesis. Despite the identification of a large number of potentially pathogenic variants in the mitochondrially encoded rRNA (mt-rRNA) genes, we lack direct methods to firmly establish their pathogenicity. In the absence of such methods, we have devised an indirect approach named heterologous inferential analysis (HIA ) that can be used to make predictions concerning the disruptive potential of a large subset of mt-rRNA variants. We have used HIA to explore the mutational landscape of 12S and 16S mt-rRNA genes. Our HIA studies include a thorough classification of all rare variants reported in the literature as well as others obtained from studies performed in collaboration with physicians. HIA has also been used with non-mammalian mt-rRNA genes to elucidate how mitotypes influence the interaction of the individual and the environment. Regarding mt-tRNA variations, rapidly growing evidence shows that the spectrum of mutations causing mitochondrial disease might differ between the different mitochondrial haplogroups seen in human populations.


Assuntos
Biologia Computacional/métodos , DNA Mitocondrial/genética , Genômica/métodos , Doenças Mitocondriais/genética , RNA Mitocondrial/genética , Humanos , Mutação , Biossíntese de Proteínas , RNA Ribossômico , RNA Ribossômico 16S , RNA de Transferência/genética
11.
Methods Mol Biol ; 2277: 331-343, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34080160

RESUMO

We describe a protocol to prepare a multiplexed mtDNA library from a blood sample for performing a long read sequencing of the mitochondrial genome. All steps are carefully described to get a high enrichment of mtDNA relative to total DNA extracted from the blood sample. The obtained mutiplexed library allows the production of long sequence mtDNA reads up to 16.5 kbp with a quality enabling variant-calling by using a portable sequencer (MinION, Oxford Nanopore Technologies).


Assuntos
DNA Mitocondrial/genética , Genoma Mitocondrial , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Coleta de Amostras Sanguíneas , Biblioteca Gênica , Sequenciamento de Nucleotídeos em Larga Escala/instrumentação , Humanos
12.
Methods Mol Biol ; 2277: 299-329, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34080159

RESUMO

In light of accumulating evidence suggestive of cell type-specific vulnerabilities as a result of normal aging processes that adversely affect the brain, as well as age-related neurodegenerative disorders such as Parkinson's disease (PD), the current chapter highlights how we study mitochondrial DNA (mtDNA) changes at a single-cell level. In particular, we comment on increasing questioning of the narrow neurocentric view of such pathologies, where microglia and astrocytes have traditionally been considered bystanders rather than players in related pathological processes. Here we review the contribution made by single-cell mtDNA alterations towards neuronal vulnerability seen in neurodegenerative disorders, focusing on PD as a prominent example. In addition, we give an overview of methodologies that support such experimental investigations. In considering the significant advances that have been made in recent times for developing mitochondria-specific therapies, investigations to account for cell type-specific mitochondrial patterns and how these are altered by disease hold promise for delivering more effective disease-modifying therapeutics.


Assuntos
Encéfalo/patologia , DNA Mitocondrial/análise , DNA Mitocondrial/genética , Doenças Neurodegenerativas/patologia , Análise de Célula Única/métodos , Envelhecimento/genética , Humanos , Doenças Neurodegenerativas/genética , Doença de Parkinson/genética , Reação em Cadeia da Polimerase/métodos
13.
Methods Mol Biol ; 2277: 433-447, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34080167

RESUMO

In recent years, next-generation sequencing (NGS) has become a powerful tool for studying both inherited and somatic heteroplasmic mitochondrial DNA (mtDNA) variation. NGS has proved particularly powerful when combined with single-cell isolation techniques, allowing the investigation of low-level heteroplasmic variants both between cells and within tissues. Nevertheless, there remain significant challenges, especially around the selective enrichment of mtDNA from total cellular DNA and the avoidance of nuclear pseudogenes. This chapter summarizes the techniques needed to enrich, amplify, sequence, and analyse mtDNA using NGS .


Assuntos
DNA Mitocondrial/genética , DNA Mitocondrial/isolamento & purificação , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Animais , Microdissecção e Captura a Laser , Mitocôndrias Musculares/genética , Músculo Esquelético/citologia , Reação em Cadeia da Polimerase/métodos
14.
FASEB J ; 35(7): e21694, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34165220

RESUMO

Among cardiovascular disease (CVD) biomarkers, the mitochondrial DNA copy number (mtDNAcn) is a promising candidate. A growing attention has been also dedicated to trimethylamine-N-oxide (TMAO), an oxidative derivative of the gut metabolite trimethylamine (TMA). With the aim to identify biomarkers predictive of CVD, we investigated TMA, TMAO, and mtDNAcn in a population of 389 coronary artery disease (CAD) patients and 151 healthy controls, in association with established risk factors for CVD (sex, age, hypertension, smoking, diabetes, glomerular filtration rate [GFR]) and troponin, an established marker of CAD. MtDNAcn was significantly lower in CAD patients; it correlates with GFR and TMA, but not with TMAO. A biomarker including mtDNAcn, sex, and hypertension (but neither TMA nor TMAO) emerged as a good predictor of CAD. Our findings support the mtDNAcn as a promising plastic biomarker, useful to monitor the exposure to risk factors and the efficacy of preventive interventions for a personalized CAD risk reduction.


Assuntos
Biomarcadores/sangue , Doenças Cardiovasculares/diagnóstico , Variações do Número de Cópias de DNA , DNA Mitocondrial/sangue , Trato Gastrointestinal/metabolismo , Metilaminas/sangue , Idoso , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/genética , Estudos de Casos e Controles , Estudos de Coortes , DNA Mitocondrial/genética , Feminino , Humanos , Masculino , Fatores de Risco
15.
Int J Mol Sci ; 22(10)2021 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-34065857

RESUMO

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.


Assuntos
DNA Mitocondrial/genética , Mitocôndrias/genética , Neoplasias/genética , Progressão da Doença , Complexo I de Transporte de Elétrons/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Predisposição Genética para Doença , Humanos , Mutação , Neoplasias/metabolismo , Polimorfismo Genético , Espécies Reativas de Oxigênio/metabolismo
16.
Int J Mol Sci ; 22(11)2021 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-34072215

RESUMO

In this paper, we present a new algorithm for alignment and haplogroup estimation of mitochondrial DNA (mtDNA) sequences. Based on 26,011 vetted full mitogenome sequences, we refined the 5435 original haplogroup motifs of Phylotree Build 17 without changing the haplogroup nomenclature. We adapted 430 motifs (about 8%) and added 966 motifs for yet undetermined subclades. In summary, this led to an 18% increase of haplogroup defining motifs for full mitogenomes and a 30% increase for the mtDNA control region that is of interest for a variety of scientific disciplines, such as medical, population and forensic genetics. The new algorithm is implemented in the EMPOP mtDNA database and is freely accessible.


Assuntos
DNA Mitocondrial/genética , Haplótipos , Filogenia , Algoritmos , Biologia Computacional/métodos , DNA Mitocondrial/química , Genoma Mitocondrial , Genômica/métodos , Humanos , Mitocôndrias/genética , Sequências Reguladoras de Ácido Nucleico
17.
Int J Mol Sci ; 22(11)2021 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-34070501

RESUMO

Our goal was to analyze postmortem tissues of an adult patient with late-onset thymidine kinase 2 (TK2) deficiency who died of respiratory failure. Compared with control tissues, we found a low mtDNA content in the patient's skeletal muscle, liver, kidney, small intestine, and particularly in the diaphragm, whereas heart and brain tissue showed normal mtDNA levels. mtDNA deletions were present in skeletal muscle and diaphragm. All tissues showed a low content of OXPHOS subunits, and this was especially evident in diaphragm, which also exhibited an abnormal protein profile, expression of non-muscular ß-actin and loss of GAPDH and α-actin. MALDI-TOF/TOF mass spectrometry analysis demonstrated the loss of the enzyme fructose-bisphosphate aldolase, and enrichment for serum albumin in the patient's diaphragm tissue. The TK2-deficient patient's diaphragm showed a more profound loss of OXPHOS proteins, with lower levels of catalase, peroxiredoxin 6, cytosolic superoxide dismutase, p62 and the catalytic subunits of proteasome than diaphragms of ventilated controls. Strong overexpression of TK1 was observed in all tissues of the patient with diaphragm showing the highest levels. TK2 deficiency induces a more profound dysfunction of the diaphragm than of other tissues, which manifests as loss of OXPHOS and glycolytic proteins, sarcomeric components, antioxidants and overactivation of the TK1 salvage pathway that is not attributed to mechanical ventilation.


Assuntos
DNA Mitocondrial/genética , DNA Mitocondrial/metabolismo , Diafragma/metabolismo , Mitocôndrias/metabolismo , Insuficiência Respiratória/metabolismo , Timidina Quinase/deficiência , Timidina Quinase/genética , Actinas/metabolismo , Adulto , Autopsia , Encéfalo/metabolismo , Catalase/metabolismo , Diafragma/enzimologia , Feminino , Frutose-Bifosfato Aldolase/metabolismo , Gliceraldeído-3-Fosfato Desidrogenase (Fosforiladora)/metabolismo , Humanos , Intestino Delgado/metabolismo , Rim/metabolismo , Fígado/metabolismo , Espectrometria de Massas , Mitocôndrias/enzimologia , Mitocôndrias/genética , Músculo Esquelético/metabolismo , Fosforilação Oxidativa , Peroxirredoxina VI/metabolismo , Complexo de Endopeptidases do Proteassoma , Proteoma/genética , Proteoma/metabolismo , Insuficiência Respiratória/genética , Insuficiência Respiratória/mortalidade , Superóxido Dismutase/metabolismo , Timidina Quinase/metabolismo , Regulação para Cima
18.
Methods Mol Biol ; 2277: 1-13, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34080141

RESUMO

Progress in animal modeling of polymorphisms and mutations in mitochondrial DNA (mtDNA) is not as developed as nuclear transgenesis due to a host of cellular and physiological distinctions. mtDNA mutation modeling is of critical importance as mutations in the mitochondrial genome give rise to a variety of pathological conditions and play a contributing role in many others. Nuclear localization and transcription of mtDNA genes followed by cytoplasmic translation and transport into mitochondria (allotopic expression, AE) provide an opportunity to create in vivo modeling of a targeted mutation in mitochondrial genes. Accordingly, such technology has been suggested as a strategy for gene replacement therapy in patients harboring mitochondrial DNA mutations. Here, we use our AE approach to transgenic mouse modeling of the pathogenic human T8993G mutation in mtATP6 as a case study for designing AE animal models.


Assuntos
Mitocôndrias/metabolismo , Doenças Mitocondriais/metabolismo , ATPases Mitocondriais Próton-Translocadoras/metabolismo , Animais , DNA Mitocondrial/genética , DNA Mitocondrial/metabolismo , Modelos Animais de Doenças , Humanos , Camundongos , Camundongos Transgênicos , Mitocôndrias/genética , Doenças Mitocondriais/genética , Doenças Mitocondriais/patologia , ATPases Mitocondriais Próton-Translocadoras/genética , Mutação
19.
BMC Ecol Evol ; 21(1): 121, 2021 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-34134613

RESUMO

BACKGROUND: Delimiting cryptic species in elasmobranchs is a major challenge in modern taxonomy due the lack of available phenotypic features. Employing stand-alone genetics in splitting a cryptic species may prove problematic for further studies and for implementing conservation management. In this study, we examined mitochondrial DNA and genome-wide nuclear single nucleotide polymorphisms (SNPs) in the brown-banded bambooshark, Chiloscyllium punctatum to evaluate potential cryptic species and the species-population boundary in the group. RESULTS: Both mtDNA and SNP analyses showed potential delimitation within C. punctatum from the Indo-Australian region and consisted of four operational taxonomic units (OTUs), i.e. those from Indo-Malay region, the west coast of Sumatra, Lesser Sunda region, and the Australian region. Each OTU can be interpreted differently depending on available supporting information, either based on biological, ecological or geographical data. We found that SNP data provided more robust results than mtDNA data in determining the boundary between population and cryptic species. CONCLUSION: To split a cryptic species complex and erect new species based purely on the results of genetic analyses is not recommended. The designation of new species needs supportive diagnostic morphological characters that allow for species recognition, as an inability to recognise individuals in the field creates difficulties for future research, management for conservation and fisheries purposes. Moreover, we recommend that future studies use a comprehensive sampling regime that encompasses the full range of a species complex. This approach would increase the likelihood of identification of operational taxonomic units rather than resulting in an incorrect designation of new species.


Assuntos
Tubarões , Animais , Austrália , DNA Mitocondrial/genética , Indonésia , Filogenia , Polimorfismo de Nucleotídeo Único , Tubarões/genética
20.
Zool Res ; 42(4): 389-400, 2021 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-34047079

RESUMO

The flying squirrels (Pteromyini, Rodentia) are the most diverse and widely distributed group of gliding mammals. Taxonomic boundaries and relationships within flying squirrels remain an area of active research in mammalogy. The discovery of new specimens of Pteromys ( Hylopetes) leonardi Thomas, 1921 previously considered a synonym of Hylopetes alboniger, in Yunnan Province, China allowed a morphological and genetic reassessment of the status of this taxon. Phylogenetic reconstruction was implemented using sequences of two mitochondrial (12S ribosomal DNA and 16S ribosomal DNA) and one nuclear (interphotoreceptor retinoid-binding protein) gene fragments. Morphological assessments involved examinations of features preserved on skins, skulls, and penises of museum specimens, supplemented with principal component analysis of craniometric data. Together these assessments revealed that this taxon should be recognized not only as a distinct species, and should also be placed within a new genus, described here as Priapomys.


Assuntos
Sciuridae/classificação , Animais , China , DNA Mitocondrial/genética , Filogenia , RNA Ribossômico/genética , Sciuridae/anatomia & histologia , Sciuridae/genética , Especificidade da Espécie
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