The influence of double helix torsional elasticity on the compaction and structure of circular DNA compact form is studied theoretically in the case when the compact (globular) form has torus shape. For closed circular DNA the topological invariant, the linking number, yields a strict connection between conformation of the double helix considered as unifilar homopolymer and elastic energy of torsional twisting. The contribution of torsional elasticity to the free energy of the toruslike globule is calculated. This contribution is shown to be proportional to the square of superhelical density. Allowance of the torsional elasticity decreases the equilibrium radius of the toruslike globule formed by circular DNA. Closure of linear DNA into a ring widens the stability range of the relatively short DNA compact form and tightens it for long DNA.
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http://dx.doi.org/10.1080/07391102.1985.10508438 | DOI Listing |
Sci Rep
December 2024
Department of Biological Sciences, Université de Montréal, Montréal, QC, Canada.
Mitochondrial epigenetics, particularly mtDNA methylation, is a flourishing field of research. MtDNA methylation appears to play multiple roles, including regulating mitochondrial transcription, cell metabolism and mitochondrial inheritance. In animals, bivalves with doubly uniparental inheritance (DUI) of mitochondria are the exception to the rule of maternal mitochondrial inheritance since DUI also involve a paternal mtDNA transmitted from the father to sons.
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December 2024
Department of Clinical Pharmacy, College of Pharmacy, King Saud University, Riyadh, 11451, Saudi Arabia.
Focusing on the Yashkun population of Gilgit-Baltistan, an administrative territory in northern Pakistan, our study investigated mtDNA haplotypes as indicators of ancient gene flow and genetic diversity. Genomic DNA was extracted and evaluated for quality using agarose gel electrophoresis. The complete control region of mtDNA (nt 16024-576) was amplified via PCR, and sequencing was performed using the Big Dye Terminator Kit on an Applied Biosystems Genetic Analyzer.
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December 2024
Laboratório de Genética e Evolução Molecular, Universidade Federal do Espírito Santo, Vitória, ES, Brazil.
A recent study proposed a new genetic lineage of leatherback turtles (Dermochelys coriacea) based on genetic analysis, environmental history, and local ecological knowledge (LEK), suggesting the existence of two possible species or subspecies on the beaches of Oaxaca, diverging ~ 13.5 Mya. However, this hypothesis may be influenced by nuclear mitochondrial DNA segments (NUMTs), which could have been misamplified as true mtDNA.
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December 2024
College of Life sciences, Shandong First Medical University and Shandong Academy of Medical Sciences, Tai'an, 271016, China.
The mitochondrial whole genome of Phellinus igniarius was sequenced with the objective of examining the evolutionary relationships amongst related species. The entire mitochondrial genome was assembled using Illumina sequencing technology. The structural annotation and bioinformatics analysis were performed.
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December 2024
Laboratory of Fish Microbiology, Institute of Coastal Studies, Federal University of Para (UFPA), Alameda Leandro Ribeiro s/n, Braganca, 68600-000, Para, Brazil.
We evaluate the evidence of cryptic speciation in Larimus breviceps, a species widely distributed in the western South Atlantic, from the Greater Antilles to Santa Catarina in Brazil. Mitochondrial (COI, Cyt b, and Control Region) and nuclear (IGF1 and Tmo-4C4) sequences were obtained from populations in the western South Atlantic. The analysis revealed two genetically distinct, sympatric lineages with no gene flow, with L.
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