Chromosomes in the nuclei of living salivary glands of Simulium have been observed with Nomarski optics and polarized light before and during irrigation with various fixatives. All cause loss of chromosomal organization to some degree. The best fixative is redistilled glutaraldehyde; even so, although it leaves the nucleus visually unaltered, a network forms in the nuclear sap and birefringence is lost. Calcium ions in the fixative cause chromosomal movements. The fixatives may alter nucleoli and may dissolve them completely. New fixatives are needed for reliable fine-structural studies of chromosomal organization.
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http://dx.doi.org/10.1242/jcs.20.1.221 | DOI Listing |
Nucleic Acids Res
January 2025
Department of Genome Sciences, University of Virginia, PO Box 800717, Charlottesville, VA 22908, USA.
Many transcription factors (TFs) have been shown to bind to super-enhancers, forming transcriptional condensates to activate transcription in various cellular systems. However, the genomic and epigenomic determinants of phase-separated transcriptional condensate formation remain poorly understood. Questions regarding which TFs tend to associate with transcriptional condensates and what factors influence their association are largely unanswered.
View Article and Find Full Text PDFJ Comput Chem
January 2025
Regional Center of Advanced Technologies and Materials, Czech Advanced Technology and Research Institute (CATRIN), Palacký University Olomouc, Olomouc, Czech Republic.
Doxorubicin (DOX) is a widely used chemotherapeutic agent known for intercalating into DNA. However, the exact modes of DOX interactions with various DNA structures remain unclear. Using molecular dynamics (MD) simulations, we explored DOX interactions with DNA duplexes (dsDNA), G-quadruplex, and nucleosome.
View Article and Find Full Text PDFAm J Med Genet A
January 2025
Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy.
TBCK (TBC1 Domain-Containing Kinase) encodes a protein playing a role in actin organization and cell growth/proliferation via the mTOR signaling pathway. Deleterious biallelic TBCK variants cause Hypotonia, infantile, with psychomotor retardation and characteristic facies 3. We report on three affected sibs, also displaying cardiac malformations.
View Article and Find Full Text PDFJ Math Biol
January 2025
Institut universitaire de France (IUF), Paris, France.
We build and study an individual based model of the telomere length's evolution in a population across multiple generations. This model is a continuous time typed branching process, where the type of an individual includes its gamete mean telomere length and its age. We study its Malthusian's behaviour and provide numerical simulations to understand the influence of biologically relevant parameters.
View Article and Find Full Text PDFNat Commun
January 2025
Sorbonne Université, CNRS, Laboratory of Computational and Quantitative Biology, LCQB, Paris, France.
Telomere shortening ultimately causes replicative senescence. However, identifying the mechanisms driving replicative senescence in cell populations is challenging due to the heterogeneity of telomere lengths and the asynchrony of senescence onset. Here, we present a mathematical model of telomere shortening and replicative senescence in Saccharomyces cerevisiae which is quantitatively calibrated and validated using data of telomerase-deficient single cells.
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