Specific and well-organized chromosome architecture in human sperm cells is supported by the prominent interactions between centromeres and between telomeres. The telomere-telomere interactions result in telomere dimers that are positioned at the nuclear periphery. It is unknown whether composition of sperm telomere dimers is random or specific. We now report that telomere dimers result from specific interactions between the two ends of each chromosome. FISH using pairs of subtelomeric DNA probes that correspond to the small and long arms of seven human chromosomes demonstrates that subtelomeres of one chromosome are brought together. Statistical analysis confirmed that telomere associations could not result from the random proximity of DNA sequences. Therefore, chromosomes in human sperm nuclei adopt a looped conformation. This higher-order chromosome structure is most likely required for chromosome withdrawal/decondensation during the early fertilization events leading to zygote formation.
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http://dx.doi.org/10.1007/s10577-005-5513-1 | DOI Listing |
Talanta
February 2025
Pharmaceutical College, Guangxi Key Laboratory of Bioactive Molecules Research and Evaluation, Key Laboratory of Micro-Nanoscale Bioanalysis and Drug Screening of Guangxi Higher Education, Guangxi Medical University, Nanning, 530021, China.
Deferasirox (DEF) is an important iron chelator for treatment of iron overload-related diseases. Monitoring DEF concentration in human serum will provide some valuable information for clinical diagnosis and therapy of such diseases. In this study, we developed a peroxidase-mimicking colorimetric sensor for the detection of DEF by simple assembly of a telomeric dimeric G-quadruplex DNAzyme with Cu.
View Article and Find Full Text PDFJ Chem Phys
September 2024
Department of Physics and Geology, University of Perugia, via Alessandro Pascoli, 06123 Perugia, Italy.
Telomeric G-quadruplexes (G4s) are non-canonical DNA structures composed of TTAGGG repeats. They are extensively studied both as biomolecules key for genome stability and as promising building blocks and functional elements in synthetic biology and nanotechnology. This is why it is extremely important to understand how the interaction between G4s is affected by their topology.
View Article and Find Full Text PDFBiol Open
August 2024
Department of Genetics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461,USA.
The Drosophila Id gene extramacrochaetae (emc) is required during Drosophila eye development for proper cell fate specification within the R7 equivalence group. Without emc, R7 cells develop like R1/6 cells, and there are delays and deficits in differentiation of non-neuronal cone cells. Although emc encodes an Inhibitor of DNA-binding (Id) protein that is known to antagonize proneural bHLH protein function, no proneural gene is known for R7 or cone cell fates.
View Article and Find Full Text PDFbioRxiv
June 2024
Laboratory for Cell Biology and Genetics, Rockefeller University, New York, USA.
Programmed telomere shortening limits tumorigenesis through the induction of replicative senescence. Here we address three long-standing questions concerning senescence. First, we show that the ATM kinase is solely responsible for the induction of replicative senescence.
View Article and Find Full Text PDFBioTech (Basel)
April 2024
Department of Agricultural and Life Sciences, Faculty of Agriculture, Shinshu University, 8304 Minami-minowa, Kami-ina 399-4598, Japan.
A myogenetic oligodeoxynucleotide (myoDN), iSN04 (5'-AGA TTA GGG TGA GGG TGA-3'), is a single-stranded 18-base telomeric DNA that serves as an anti-nucleolin aptamer and induces myogenic differentiation, which is expected to be a nucleic acid drug for the prevention of disease-associated muscle wasting. To improve the drug efficacy and synthesis cost of myoDN, shortening the sequence while maintaining its structure-based function is a major challenge. Here, we report the novel 12-base non-telomeric myoDN, iMyo01 (5'-TTG GGT GGG GAA-3'), which has comparable myogenic activity to iSN04.
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