Search results for "heteroplasmy"

Analysis of heteroplasmy in bank voles inhabiting the Chernobyl exclusion zone : A commentary on Baker et al. (2017) "Elevated mitochondrial genome v…

2018

Mitochondrial heteroplasmy in an avian hybrid form (Passer italiae: Aves, Passeriformes)

2019

Mitochondrial heteroplasmy is the result from biparental transmission of mitochondrial DNA (mtDNA) to the offspring. In such rare cases, maternal and paternal mtDNA is present in the same individual. Though recent studies suggested that mtDNA heteroplasmy might be more common than previously anticipated, that phenomenon is still poorly documented and was mostly detected in case studies on hybrid populations. The Italian sparrow, Passer italiae is a homoploid hybrid form that occurs all across the Italian Peninsula mostly under strict absence of either of its parent species, the house sparrow (P. domesticus) and the Spanish sparrow (P. hispaniolensis). In this study, we document a new case o…

The link between mitochondrial DNA hypervariable segment I heteroplasmy and ageing among genetically unrelated Latvians

2011

International audience; Various studies have demonstrated that mitochondrial DNA (mtDNA) heteroplasmy tends to increase with age and that the observed frequency of heteroplasmy among populations mostly depends on the way it is measured. Therefore, we investigated age-related association on the presence of mtDNA heteroplasmy within the hypervariable segment 1 (HVS-I) in a selected study group. The study group consisted of 300 maternally unrelated Latvians ranging in age from 18 to over 90years. To determine the optimal method for mtDNA heteroplasmy detection, three approaches were used: (i) SURVEYORTM Mutation Detection Kit, (ii) sequencing and (iii) denaturing gradient-gel electrophoresis (…

First mitochondrial genome-wide association study with metabolomics.

2021

AbstractIn the era of personalized medicine with more and more patient-specific targeted therapies being used, we need reliable, dynamic, faster and sensitive biomarkers both to track the causes of disease and to develop and evolve therapies during the course of treatment. Metabolomics recently has shown substantial evidence to support its emerging role in disease diagnosis and prognosis. Aside from biomarkers and development of therapies, it is also an important goal to understand the involvement of mitochondrial DNA (mtDNA) in metabolic regulation, aging and disease development. Somatic mutations of the mitochondrial genome are also heavily implicated in age-related disease and aging. The…

Results of a collaborative study of the EDNAP group regarding mitochondrial DNA heteroplasmy and segregation in hair shafts.

2004

Abstract A collaborative exercise was carried out by the European DNA Profiling Group (EDNAP) in order to evaluate the distribution of mitochondrial DNA (mtDNA) heteroplasmy amongst the hairs of an individual who displays point heteroplasmy in blood and buccal cells. A second aim of the exercise was to study reproducibility of mtDNA sequencing of hairs between laboratories using differing chemistries, further to the first mtDNA reproducibility study carried out by the EDNAP group [Forensic Sci. Int. 97 (1998) 165]. Laboratories were asked to type 2 sections from each of 10 hairs, such that each hair was typed by at least two laboratories. Ten laboratories participated in the study, and a to…

Chronic progressive external ophthalmoplegia with a novel mitochondrial DNA deletion and a mutation in the tRNALEU(UUR) gene

1999

Large-scale deletions and point mutations of the mitochondrial DNA are generally accepted as being involved in the pathogenesis of diseases associated with mitochondrial encephalomyopathies such as Kearns-Sayre syndrome and chronic progressive external ophthalmoplegia (CPEO). We screened suspected patients using polymerase chain reaction techniques, Southern blot analyses, and muscle biopsy specimens. We report on a novel 4,953-base pair deletion associated with a familial occurrence of a tRNA Leu(UUR) T3250C point mutation in a young female patient clinically diagnosed with CPEO. This deletion is not flanked by direct repeats, so slip replication and homologous recombination do not seem li…

No evidence of DUI in the Mediterranean alien species Brachidontes pharaonis (P. Fisher, 1870) despite mitochondrial heteroplasmy

2022

AbstractTwo genetically different mitochondrial haplogroups of Brachidontes pharaonis (p-distance 6.8%) have been identified in the Mediterranean Sea. This hinted at a possible presence of doubly uniparental inheritance in this species. To ascertain this possibility, we sequenced two complete mitogenomes of Brachidontes pharaonis mussels and performed a qPCR analysis to measure the relative mitogenome copy numbers of both mtDNAs. Despite the presence of two very similar regions composed entirely of repetitive sequences in the two haplogroups, no recombination between mitogenomes was detected. In heteroplasmic individuals, both mitogenomes were present in the generative tissues of both sexes…

A new mitochondrial point mutation in the transfer RNALys gene associated with progressive external ophthalmoplegia with impaired respiratory regulat…

2011

Abstract We report a novel heteroplasmic point mutation G8299A in the gene for mitochondrial tRNA Lys in a patient with progressive external ophthalmoplegia complicated by recurrent respiratory insufficiency. Biochemical analysis of respiratory chain complexes in muscle homogenate showed a combined complex I and IV deficiency. The transition does not represent a known neutral polymorphism and affects a position in the tRNA acceptor stem which is conserved in primates, leading to a destabilization of this functionally important domain. In vitro analysis of an essential maturation step of the tRNA transcript indicates the probable pathogenicity of this mutation. We hypothesize that there is a…

Sequence polymorphism of mitochondrial DNA control region in Japanese.

1998

Sequence polymorphisms of the mitochondrial DNA (mtDNA) control region, hypervariable regions I and II, from 100 unrelated Japanese were determined by PCR amplification and direct sequencing. Sequences of 404 nucleotides for hypervariable region I and 379 nucleotides for region II were obtained. Variable sites (85 and 45) were revealed in region I and region II, respectively, as compared to the reference sequence, and a total of 96 different genetic patterns from both regions I and II were determined. A point mutation heteroplasmy was observed at the ratio of approximately 50:50 from one individual at the sequence position 151 showing a nucleotide transition from C to T. The probability of …

New Insights Into Mitochondrial DNA Reconstruction and Variant Detection in Ancient Samples

2021

Ancient DNA (aDNA) studies are frequently focused on the analysis of the mitochondrial DNA (mtDNA), which is much more abundant than the nuclear genome, hence can be better retrieved from ancient remains. However, postmortem DNA damage and contamination make the data analysis difficult because of DNA fragmentation and nucleotide alterations. In this regard, the assessment of the heteroplasmic fraction in ancient mtDNA has always been considered an unachievable goal due to the complexity in distinguishing true endogenous variants from artifacts. We implemented and applied a computational pipeline for mtDNA analysis to a dataset of 30 ancient human samples from an Iron Age necropolis in Poliz…