98%
921
2 minutes
20
We have formed new short telomeres in using an inducible nuclease that cuts near telomere repeats in cells that lack, cannot recruit or cannot fully activate telomerase. Sequencing these new telomeres showed that cells can divide at least 4 times with ~30 bp of non-telomeric sequence at the chromosome end in cells lacking telomerase, which contrasts with current models for the roles of terminal single-stranded telomere repeats and the telomere proteins in telomere protection and replication. Cells that cannot recruit or activate telomerase had similar results, with additional terminal truncations or telomere repeat addition.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC12163625 | PMC |
http://dx.doi.org/10.17912/micropub.biology.001622 | DOI Listing |
Front Biosci (Landmark Ed)
August 2025
Laboratory of Molecular Biology, Research Centre for Medical Genetics (RCMG), 115522 Moscow, Russia.
Background: Schizophrenia (SZ) is associated with chronic oxidative stress in the patient's body. Previous studies revealed an increased copy number of genes for 47S pre-ribosomal RNA (pre-rRNA) in SZ patients. In this study, levels of oxidative stress and factors involved in the adaptive response to chronic stress (rDNA transcription) were, for the first time, compared in blood cells of patients with catatonic SZ(C) and paranoid SZ(P), chronic forms of schizophrenia, as well as healthy controls (HC).
View Article and Find Full Text PDFFront Plant Sci
August 2025
Department of Plant Developmental Genetics, Institute of Biophysics of the Czech Academy of Sciences, Brno, Czechia.
Introduction: Satellite DNA (satDNA) is a rapidly evolving component of plant genomes, typically found in (peri)centromeric, (sub)telomeric, and other heterochromatic regions. Due to their variability and species- or population-specific distribution, satDNA serves as valuable cytogenetic markers for studying chromosomal rearrangements and karyotype evolution among closely related species. Previous studies have identified species-specific subtelomeric repeats CS-1 in , HSR1 in , and HJSR in .
View Article and Find Full Text PDFbioRxiv
August 2025
Department of Genetics and Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
Extremely short telomeres cause bone marrow failure in telomere biology disorder (TBDs) patients. Here, we employed the recently developed 'Telomouse' with human-length telomeres resulting from a single amino acid substitution in the helicase Rtel1 ( ) to determine the effects of the short telomeres on the bone marrow and hematopoiesis. Under homeostatic conditions, Telomice have notably short telomeres but normal hematopoiesis.
View Article and Find Full Text PDFBiochemistry
September 2025
Department of Chemistry, Oakland University, Rochester, Michigan 48309, United States.
BRCA1 is a crucial component of homologous recombination (HR), a high-fidelity pathway for repairing double-stranded DNA breaks (DSBs) in human cells. The central region of the BRCA1 protein contains two putative DNA binding domains (DBDs), yet their relative substrate specificities and functional contributions to HR remain unclear. Here, we characterized the DNA binding properties of DBD1 (amino acids 330-554), DBD2 (amino acids 894-1057), and BRCA1 C-terminal (BRCT) repeats using biolayer interferometry.
View Article and Find Full Text PDFBiochem Biophys Rep
September 2025
Nucleic Acids Research Lab, Department of Chemistry, University of Delhi (North Campus), Delhi, 110007, India.
DNA is polymorphic, as with four nucleobases, it can be configured in a number of secondary structures. The four-stranded DNA structures consisting of G-tetrads have especially been intriguing because of their proven existence in human cells. Due to the high prevalence of putative G-quadruplex-forming sequence motifs in the human genome, scientists in recent years have highlighted the potential of exploiting these exotic structures for targeted therapies for various cancers.
View Article and Find Full Text PDF