scholarly journals The first concurrent detection of mitochondrial DNA m.3243A>G mutation, deletion, and depletion in a family with mitochondrial diabetes

2020 ◽  
Vol 8 (7) ◽  
Author(s):  
Mouna Tabebi ◽  
Wajdi Safi ◽  
Rahma Felhi ◽  
Olfa Alila Fersi ◽  
Leila Keskes ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Mitochondrial Diabetes

scholarly journals Clinical phenotype of mitochondrial diabetes due to rare mitochondrial DNA mutations

2020 ◽  
Vol 81 (2-3) ◽  
pp. 68-77
Author(s):  
Anne-Gaëlle Decoux-Poullot ◽  
Sylvie Bannwarth ◽  
Vincent Procaccio ◽  
Anne-Sophie Lebre ◽  
Claude Jardel ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Clinical Phenotype ◽  
Mitochondrial Dna Mutations ◽  
Dna Mutations ◽  
Mitochondrial Diabetes

scholarly journals Mitochondrial diabetes and mitochondrial DNA mutation load in MELAS syndrome

2020 ◽  
Vol 183 (5) ◽  
pp. 505-512
Author(s):  
Hyun-Wook Chae ◽  
Ji-Hoon Na ◽  
Ho-Seong Kim ◽  
Young-Mock Lee
Keyword(s):  
Insulin Resistance ◽  
Mitochondrial Dna ◽  
Clinical Severity ◽  
Mutational Load ◽  
Melas Syndrome ◽  
Young Adolescents ◽  
Mutation Load ◽  
Mitochondrial Diabetes ◽  
Children And Young Adolescents

Objective: Mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome is a very rare condition; it encompasses a diverse group of disorders including diabetes. Phenotypic variability can be attributed to heteroplasmy along with varying proportions of mutant and WT mitochondrial DNA (mtDNA). To examine the clinical relationship between mitochondrial diabetes and mutational load, we analyzed the mtDNA of children and young adolescents with MELAS syndrome using next generation sequencing (NGS). Design and methods: Of 57 subjects with suspected MELAS syndrome, 32 children and young adolescents were diagnosed as MELAS syndrome with mtDNA A-to-G transition at nucleotide 3243. Mutation load studies and NGS were performed for 25 subjects. Results: The mean mutation load was 60.4 ± 18.4% (range: 22.5‒100). Of the 25 subjects with NGS results, 15 (60%) were diagnosed with DM and 2 (8%) were diagnosed with impaired glucose tolerance (IGT). The mutational load of subjects inversely correlated with first symptom onset, age at diagnosis of MELAS syndrome, and DM (P < 0.001). However, mutational load did not correlate with the clinical severity or progression of DM/IGT. There was no significant difference in insulin resistance or sensitivity indices between the low- and high-mutation load groups. During the 3.7 years of follow-up, insulin resistance indices were not significantly different between baseline and follow-up. Conclusions: We can infer that the mutation load in the MELAS syndrome is significantly associated with the onset of symptoms and associated diseases, including mitochondrial diabetes. However, it may not influence disease progression.

Evaluation of the dark field method for large association of spread DNA

1978 ◽  
Vol 36 (2) ◽  
pp. 190-191
Author(s):  
Douglas C. Barker
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Mitochondrial Dna ◽  
Extraction Method ◽  
Field Method ◽  
Dark Field ◽  
Kinetoplast Dna ◽  
Field Electron ◽  
Field Electron Microscopy ◽  
Dark Field Electron

A number of satisfactory methods are available for the electron microscopy of nicleic acids. These methods concentrated on fragments of nuclear, viral and mitochondrial DNA less than 50 megadaltons, on denaturation and heteroduplex mapping (Davies et al 1971) or on the interaction between proteins and DNA (Brack and Delain 1975). Less attention has been paid to the experimental criteria necessary for spreading and visualisation by dark field electron microscopy of large intact issociations of DNA. This communication will report on those criteria in relation to the ultrastructure of the (approx. 1 x 10-14g) DNA component of the kinetoplast from Trypanosomes. An extraction method has been developed to eliminate native endonucleases and nuclear contamination and to isolate the kinetoplast DNA (KDNA) as a compact network of high molecular weight. In collaboration with Dr. Ch. Brack (Basel [nstitute of Immunology), we studied the conditions necessary to prepare this KDNA Tor dark field electron microscopy using the microdrop spreading technique.

Properties of Isolated Mitochondria of Agaricus Bisporus: Their Relationship to Dormancy and the Germination of Spores

1973 ◽  
Vol 31 ◽  
pp. 458-459
Author(s):  
K. S. McCarty ◽  
R. F. Weave ◽  
L. Kemper ◽  
F. S. Vogel
Keyword(s):  
Mitochondrial Dna ◽  
Ethidium Bromide ◽  
Microscopic Examination ◽  
Agaricus Bisporus ◽  
Osmotic Shock ◽  
Electron Microscopic Examination ◽  
Electron Microscopic ◽  
Isolated Mitochondria ◽  
Dna Strands ◽  
Cytoplasmic Ribosomes

During the prodromal stages of sporulation in the Basidiomycete, Agaricus bisporus, mitochondria accumulate in the basidial cells, zygotes, in the gill tissues prior to entry of these mitochondria, together with two haploid nuclei and cytoplasmic ribosomes, into the exospores. The mitochondria contain prominent loci of DNA [Fig. 1]. A modified Kleinschmidt spread technique1 has been used to evaluate the DNA strands from purified whole mitochondria released by osmotic shock, mitochondrial DNA purified on CsCl gradients [density = 1.698 gms/cc], and DNA purified on ethidium bromide CsCl gradients. The DNA appeared as linear strands up to 25 u in length and circular forms 2.2-5.2 u in circumference. In specimens prepared by osmotic shock, many strands of DNA are apparently attached to membrane fragments [Fig. 2]. When mitochondria were ruptured in hypotonic sucrose and then fixed in glutaraldehyde, the ribosomes were released for electron microscopic examination.

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