By a rapid PCR-based method to assess the 8344 mtDNA mutation associated with MERRF disease, we have studied DNA from blood samples of 10 individuals belonging to a family spanning four generations in which one patient showed the complete MERRF phenotype, three other members were less severely affected, while the remaining were unaffected. The percentage of mutant mtDNA was quantified by laser-densitometric scanning of the negative photographic sheets of the agarose gels. The results showed that the MERRF patient had 53% of mutated mtDNA while the two less affected patients had 62% and 14% of mutated mtDNA, respectively. However, a high percentage of mutated genomes (up to 64%) was also found in some unaffected relatives. These results show that although on one hand the mutation is probably the primary cause of the disease, on the other hand the relative amount of mutated mtDNA in blood samples is not indicative of its clinical expression.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1111/j.1600-0404.1993.tb05368.x | DOI Listing |
Sci China Life Sci
January 2025
Institute of Rare Diseases, West China Hospital of Sichuan University, Sichuan University, Chengdu, 610000, China.
Human mitochondrial DNA (mtDNA) harbors essential mutations linked to aging, neurodegenerative diseases, and complex muscle disorders. Due to its uniparental and haploid inheritance, mtDNA captures matrilineal evolutionary trajectories, playing a crucial role in population and medical genetics. However, critical questions about the genomic diversity patterns, inheritance models, and evolutionary and medical functions of mtDNA remain unresolved or underexplored, particularly in the transition from traditional genotyping to large-scale genomic analyses.
View Article and Find Full Text PDFNature
January 2025
Changping Laboratory, Beijing, The People's Republic of China.
The development of animal models is crucial for studying and treating mitochondrial diseases. Here we optimized adenine and cytosine deaminases to reduce off-target effects on the transcriptome and the mitochondrial genome, improving the accuracy and efficiency of our newly developed mitochondrial base editors (mitoBEs). Using these upgraded mitoBEs (version 2 (v2)), we targeted 70 mouse mitochondrial DNA mutations analogous to human pathogenic variants, establishing a foundation for mitochondrial disease mouse models.
View Article and Find Full Text PDFNature
January 2025
Division of Cell Therapy, Chiba Cancer Center Research Institute, Chiba, Japan.
Cancer cells in the tumour microenvironment use various mechanisms to evade the immune system, particularly T cell attack. For example, metabolic reprogramming in the tumour microenvironment and mitochondrial dysfunction in tumour-infiltrating lymphocytes (TILs) impair antitumour immune responses. However, detailed mechanisms of such processes remain unclear.
View Article and Find Full Text PDFPlant mitochondrial and plastid genomes have exceptionally slow rates of sequence evolution, and recent work has identified an unusual member of the gene family ("plant ") as being instrumental in preventing point mutations in these genomes. However, the eXects of disrupting -mediated DNA repair on "germline" mutation rates have not been quantified. Here, we used mutation accumulation (MA) lines to measure mutation rates in mutants and matched wild type (WT) controls.
View Article and Find Full Text PDFAnalyst
January 2025
College of Chemistry, Chemical Engineering and Material Science, Soochow University, 199 Ren'Ai Road, Suzhou 215123, China.
Most current nucleic acid-responsive fluorescent probes are enhanced ones with short emission wavelengths. Therefore, the development of novel near-infrared, turn-on response nucleic acid fluorescent probes is of great significance. Herein, three cationic fluorescent dyes 1a-1c were synthesized by reacting naphthalidine salt with suitable aldehydes.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!