The occurrence and types of complex forms and replicative intermediates of mitochondrial DNA (mtDNA) were investigated in tissues from C57BL/6J mice aged 10-11 months or 29-30 months. Total mtDNA from brain, heart, kidney and liver was isolated in ethidium bromide-CsCl gradients and examined by electron microscopy after aqueous or formamide spreading. Contour length measurements indicated no difference in the monomer size of mtDNA according to either tissue or donor age. The frequencies of catenated mtDNA, ranging from 4 to 8%, varied significantly according to tissue but changed relatively little as a result of donor age. The main age-related effect observed in this study was a significant increase in the frequency of circular dimers, from about 0.05% in adult tissues to 0.3% in kidney, 0.5% in liver, 0.6% in heart and 1.9% in brain of senescent mice. The frequency of D-loop DNA varied from 30 to 60% and that of larger replicative intermediates from 1 to 10%, suggesting differences in the rate of mtDNA replication according to tissue. The frequencies and types of the various replicative intermediates were unaffected by donor age.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC343757 | PMC |
http://dx.doi.org/10.1093/nar/4.5.1301 | DOI Listing |
Circ Cardiovasc Qual Outcomes
January 2025
Department of Epidemiology, Tulane University School of Public Health and Tropical Medicine, New Orleans, LA. (L.T., K.S.D., K.P.T., J.D.B.).
Background: Food insecurity is associated with high morbidity and mortality and is typically measured with the 10-item US Adult Food Security Survey Module. Shorter instruments may capture similar information, but this has not been validated against mortality in general populations.
Methods: A nationally representative sample of individuals aged 20 to 74 years from the US National Health Interview Survey 2011 to 2018 was included, with deaths linked to the National Death Index through 2019.
Nat Commun
January 2025
DNA Replication Group, Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, UK.
Human DNA licensing initiates replication fork assembly and DNA replication. This reaction promotes the loading of the hMCM2-7 complex on DNA, which represents the core of the replicative helicase that unwinds DNA during S-phase. Here, we report the reconstitution of human DNA licensing using purified proteins.
View Article and Find Full Text PDFLife Sci Alliance
March 2025
https://ror.org/01kj2bm70 Mitochondrial Research Group, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
Pathogenic variants in cytochrome oxidase assembly factor 5 (COA5), a proposed complex IV (CIV) assembly factor, have been shown to cause clinical mitochondrial disease with two siblings affected by neonatal hypertrophic cardiomyopathy manifesting a rare, homozygous missense variant (NM_001008215.3: c.157G>C, p.
View Article and Find Full Text PDFViruses
November 2024
Department of Veterinary Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA.
Recently, using a panel of recombinant CHO cell lines, we identified the coxsackie and adenovirus receptor (CAR) and histo-blood group antigens (HBGAs) or sialic acid as the minimum requirement for susceptibility to rhesus enteric calicivirus (ReCV) infections. While ReCVs cause lytic infection in LLC-MK2 cells, recombinant CHO (rCHO) cell lines did not exhibit any morphological changes upon infection. To monitor infectious virus production, rCHO cell cultures had to be freeze-thawed and titrated on LLC-MK2 monolayers.
View Article and Find Full Text PDFChem Res Toxicol
January 2025
SB RAS Institute of Chemical Biology and Fundamental Medicine, 8 Lavrentieva Avenue, Novosibirsk 630090, Russia.
Biological polyamines, such as spermine, spermidine, and putrescine, are abundant intracellular compounds mostly bound to nucleic acids. Due to their nucleophilic nature, polyamines easily react with apurinic/apyrimidinic (AP) sites, DNA lesions that are constantly formed in DNA by spontaneous base loss and as intermediates of base excision repair. A covalent intermediate is formed, promoting DNA strand cleavage at the AP site, and is later hydrolyzed regenerating the polyamine.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!