Mitophagy is the selective elimination of mitochondria through autophagy Recent studies have uncovered the molecular mechanisms mediating mitophagy in yeast and mammalian cells and have revealed that the dysregulation of one of these mechanisms — the PINK1–parkin-mediated signalling pathway — may contribute to Parkinson's disease

/pdf/mechanisms-of-mitophagy-evi78v27hj.pdf

Mechanisms of mitophagy

The seminal importance of DNA sequencing to the life sciences, biotechnology and medicine has driven the search for more scalable and lower-cost solutions. Here we describe a DNA sequencing technology in which scalable, low-cost semiconductor manufacturing techniques are used to make an integrated circuit able to directly perform non-optical DNA sequencing of genomes. Sequence data are obtained by directly sensing the ions produced by template-directed DNA polymerase synthesis using all-natural nucleotides on this massively parallel semiconductor-sensing device or ion chip. The ion chip contains ion-sensitive, field-effect transistor-based sensors in perfect register with 1.2 million wells, which provide confinement and allow parallel, simultaneous detection of independent sequencing reactions. Use of the most widely used technology for constructing integrated circuits, the complementary metal-oxide semiconductor (CMOS) process, allows for low-cost, large-scale production and scaling of the device to higher densities and larger array sizes. We show the performance of the system by sequencing three bacterial genomes, its robustness and scalability by producing ion chips with up to 10 times as many sensors and sequencing a human genome.

/pdf/an-integrated-semiconductor-device-enabling-non-optical-4stnv5p3y9.pdf

An integrated semiconductor device enabling non-optical genome sequencing

Understanding the odd science of aging

https://pure.mpg.de/pubman/item/item_3230146_1/component/file_3230147/Chang%20et%20al..pdf

Posttranscriptional Control of T Cell Effector Function by Aerobic Glycolysis

Human mitochondrial DNA is widely used as tool in many fields including evolutionary anthropology and population history, medical genetics, genetic genealogy, and forensic science. Many applications require detailed knowledge about the phylogenetic relationship of mtDNA variants. Although the phylogenetic resolution of global human mtDNA diversity has greatly improved as a result of increasing sequencing efforts of complete mtDNA genomes, an updated overall mtDNA tree is currently not available. In order to facilitate a better use of known mtDNA variation, we have constructed an updated comprehensive phylogeny of global human mtDNA variation, based on both coding- and control region mutations. This complete mtDNA tree includes previously published as well as newly identified haplogroups, is easily navigable, will be continuously and regularly updated in the future, and is online available at http://www.phylotree.org. © 2008 Wiley-Liss, Inc.

/pdf/updated-comprehensive-phylogenetic-tree-of-global-human-448qrnrzdo.pdf

Updated Comprehensive Phylogenetic Tree of Global Human Mitochondrial DNA Variation

/pdf/reanalysis-and-revision-of-the-cambridge-reference-sequence-2tquigom15.pdf

Reanalysis and revision of the Cambridge reference sequence for human mitochondrial DNA

Mammalian mitochondrial genetics: heredity, heteroplasmy and disease

Mutations in mitochondrial DNA (mtDNA) are a common cause of genetic disease. Pathogenic mutations in mtDNA are detected in approximately 1 in 250 live births and at least 1 in 10,000 adults in the UK are affected by mtDNA disease. Treatment options for patients with mtDNA disease are extremely limited and are predominantly supportive in nature. Mitochondrial DNA is transmitted maternally and it has been proposed that nuclear transfer techniques may be an approach for the prevention of transmission of human mtDNA disease. Here we show that transfer of pronuclei between abnormally fertilized human zygotes results in minimal carry-over of donor zygote mtDNA and is compatible with onward development to the blastocyst stage in vitro. By optimizing the procedure we found the average level of carry-over after transfer of two pronuclei is less than 2.0%, with many of the embryos containing no detectable donor mtDNA. We believe that pronuclear transfer between zygotes, as well as the recently described metaphase II spindle transfer, has the potential to prevent the transmission of mtDNA disease in humans.

/pdf/pronuclear-transfer-in-human-embryos-to-prevent-transmission-4k9q0t1w16.pdf

Pronuclear transfer in human embryos to prevent transmission of mitochondrial DNA disease

Mitochondrial DNA (mtDNA) deletions are a primary cause of mitochondrial disease and are likely to have a central role in the aging of postmitotic tissues Understanding the mechanism of the formation and subsequent clonal expansion of these mtDNA deletions is an essential first step in trying to prevent their occurrence We review the previous literature and recent results from our own laboratories, and conclude that mtDNA deletions are most likely to occur during repair of damaged mtDNA rather than during replication This conclusion has important implications for prevention of mtDNA disease and, potentially, for our understanding of the aging process

What causes mitochondrial DNA deletions in human cells

Many patients with inherited mitochondrial encephalopathies have one of two pathogenic mutations of mitochondrial DNA (mtDNA): A3243G or A8344G. Individuals who harbour these mutations carry both mutant and wild-type alleles within each cell (heteroplasmy). Despite clear evidence of a direct relationship between the level of mutation and mitochondrial respiratory chain function in vitro, it has been more difficult to demonstrate a clear correlation between clinical phenotype and the level of mutant mtDNA in vivo. To address this issue, we identified 245 individuals who carry either the A3243G or A8344G mutations, and studied the relationship between the incidence of specific clinical features and the level of mutant mtDNA in blood (for A3243G, n = 73; for A8344G, n = 25) and/or skeletal muscle (for A3234G, n = 111; for A8344G, n = 55). Within this study group, the frequency of key clinical features was significantly different for individuals harbouring the A3243G and A8344G mutations. For both mutations, there was a correlation between the frequency of the more common clinical features and the level of mutant mtDNA in muscle. In contrast, we did not observe a correlation between the frequency of clinical features and the level of mutant mtDNA in blood. Therefore, measurement of the level of the A3243G and A8344G mutations in muscle will allow the identification of individuals who are at risk of developing specific complications, thus improving the prognostic advice that can be given to patients and family members who carry these mutations.

Robert N. Lightowlers

Papers

Reanalysis and revision of the Cambridge reference sequence for human mitochondrial DNA

Mammalian mitochondrial genetics: heredity, heteroplasmy and disease

Pronuclear transfer in human embryos to prevent transmission of mitochondrial DNA disease

What causes mitochondrial DNA deletions in human cells

Molecular pathology of MELAS and MERRF. The relationship between mutation load and clinical phenotypes.