Chromatid fibers obtained from cells previously treated with colchicine were found more condensed, with a 22% greater fiber diameter than those from untreated cells. Chromatid fibers obtained by the Langmir trough technique showed a greater degree of elongation than fibers obtained by simple sedimentation.
Download full-text PDF |
Source |
|---|
Publication Analysis
Top Keywords
Similar Publications
CAMSAP2 is required for bridging fiber assembly to ensure mitotic spindle assembly and chromosome segregation in human epithelial Caco-2 cells.
PLoS One
January 2025
Department of Life Science and Medical Bioscience, Laboratory of Cytoskeletal Logistics, Graduate School of Advanced Science and Engineering, Waseda University, Shinjuku, Tokyo, Japan.
In mammalian epithelial cells, cytoplasmic microtubules are mainly non-centrosomal, through the functions of the minus-end binding proteins CAMSAP2 and CAMSAP3. When cells enter mitosis, cytoplasmic microtubules are reorganized into the spindle composed of both centrosomal and non-centrosomal microtubules. The function of the CAMSAP proteins upon spindle assembly remains unknown, as these do not exhibit evident localization to spindle microtubules.
View Article and Find Full Text PDFIon-mediated condensation controls the mechanics of mitotic chromosomes.
Nat Mater
November 2024
Department of Physics and Astronomy and LaserLaB, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
During mitosis in eukaryotic cells, mechanical forces generated by the mitotic spindle pull the sister chromatids into the nascent daughter cells. How do mitotic chromosomes achieve the necessary mechanical stiffness and stability to maintain their integrity under these forces? Here we use optical tweezers to show that ions involved in physiological chromosome condensation are crucial for chromosomal stability, stiffness and viscous dissipation. We combine these experiments with high-salt histone depletion and theory to show that chromosomal elasticity originates from the chromatin fibre behaving as a flexible polymer, whereas energy dissipation can be explained by modelling chromatin loops as an entangled polymer solution.
View Article and Find Full Text PDFInhibition of topoisomerase 2 catalytic activity impacts the integrity of heterochromatin and repetitive DNA and leads to interlinks between clustered repeats.
Nat Commun
July 2024
Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton, BN1 9RH, UK.
DNA replication and transcription generate DNA supercoiling, which can cause topological stress and intertwining of daughter chromatin fibers, posing challenges to the completion of DNA replication and chromosome segregation. Type II topoisomerases (Top2s) are enzymes that relieve DNA supercoiling and decatenate braided sister chromatids. How Top2 complexes deal with the topological challenges in different chromatin contexts, and whether all chromosomal contexts are subjected equally to torsional stress and require Top2 activity is unknown.
View Article and Find Full Text PDFRecognition of centromere-specific histone Cse4 by the inner kinetochore Okp1-Ame1 complex.
EMBO Rep
December 2023
Stanford Cancer Institute, Stanford School of Medicine, Stanford, CA, USA.
Successful mitosis depends on the timely establishment of correct chromosomal attachments to microtubules. The kinetochore, a modular multiprotein complex, mediates this connection by recognizing specialized chromatin containing a histone H3 variant called Cse4 in budding yeast and CENP-A in vertebrates. Structural features of the kinetochore that enable discrimination between Cse4/CENP-A and H3 have been identified in several species.
View Article and Find Full Text PDFHelical coiling of metaphase chromatids.
Nucleic Acids Res
April 2023
Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, D-06466 Seeland, Germany.
Chromatids of mitotic chromosomes were suggested to coil into a helix in early cytological studies and this assumption was recently supported by chromosome conformation capture (3C) sequencing. Still, direct differential visualization of a condensed chromatin fibre confirming the helical model was lacking. Here, we combined Hi-C analysis of purified metaphase chromosomes, biopolymer modelling and spatial structured illumination microscopy of large fluorescently labeled chromosome segments to reveal the chromonema - a helically-wound, 400 nm thick chromatin thread forming barley mitotic chromatids.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!