The mitotic spindle faithfully separates the genetic material, and has been reverently observed for well over a century. Across eukaryotes, while the mechanisms for moving chromosomes seem quite conserved, mechanisms for assembling the spindle often seem distinct. Two major pathways for spindle assembly are known, one based on centrosomes and the other based on chromatin, and these pathways are usually considered to be fundamentally different. We review observations of spindle assembly in animals, fungi, and plants, and argue that microtubule assembly at a particular location, centrosomes, or chromatin, reflects contingent, cell-type specific factors, rather than reflecting a fundamental distinction in the process of spindle building. We hypothesize that the essential process for spindle assembly is the motor-driven organization of microtubules that accumulate in the form of dense bundles at or near the chromosomes.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5290749 | PMC |
| http://dx.doi.org/10.1007/s00709-010-0205-x | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Cytoplasmic dynein is an essential microtubule motor protein that powers organelle transport and mitotic spindle assembly. Its activity depends on dynein-dynactin-cargo adaptor complexes, such as dynein-dynactin-BicD2 (DDB), which typically function with two dynein motors. We show that mechanical tension recruits a third dynein motor via an auxiliary BicD adaptor binding the light intermediate chain of the third dynein, stabilizing multi-dynein assemblies and enhancing force generation.
View Article and Find Full Text PDFChromosome number alterations cause apoptosis and cellular hypertrophy in induced pluripotent stem cell models of embryonic epiblast cells.
Biol Open
January 2025
Manipal Institute of Regenerative Medicine, Manipal Academy of Higher Education, Manipal 576104, India.
Chromosomal aneuploidies are a major cause of developmental failure and pregnancy loss. To investigate the possible consequences of aneuploidy on early embryonic development in vitro, we focused on primed pluripotent stem cells that are relatable to the epiblast of post-implantation embryos in vivo. We used human induced pluripotent stem cells (iPSCs) as an epiblast model and altered chromosome numbers by treating with reversine, a small-molecule inhibitor of monopolar spindle 1 kinase (MSP1) that inactivates the spindle assembly checkpoint, which has been strongly implicated in chromosome mis-segregation and aneuploidy generation.
View Article and Find Full Text PDFCdkn1c orchestrates a molecular network that regulates the euploidy of the male mouse germline stem cells.
Development
January 2025
Department of Molecular Genetics, Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan.
Karyotype instability in the germline leads to infertility. Unlike the female germline, the male germline continuously produces fertile sperm throughout life. Here we present a molecular network responsible for maintaining karyotype stability in the male mouse germline.
View Article and Find Full Text PDFdeficiency in mouse oocytes during in vitro maturation increases chromosome segregation errors with a reduced BUBR1 at kinetochore.
Reprod Med Biol
January 2025
Laboratory of Animal Reproduction, Graduate School of Agricultural Sciences Yamagata University Tsuruoka Japan.
Purpose: This study aimed to investigate the molecular mechanisms associated with chromosome segregation errors caused by intrinsic oxidative stress during in vitro oocyte maturation (IVM) using oocytes from -deficient (KO) mice.
Methods: Ovulated or in vitro matured cumulus-cells oocyte complexes (COCs) were collected from wild-type (WT) and KO mice and evaluated chromosome alignment, chromosome segregation, meiotic progression, and BUBR1 and REC8 protein expression levels.
Results: In 21% O IVM, the KO had significantly higher frequencies of chromosome misalignment and segregation errors compared to the WT, and they also reached Germinal Vesicle Break Down (GVBD) and M I stages peak earlier and showed a shorter M I stage residence time compared to the WT.
ELL3 regulates spindle assembly to prevent maternally inherited aneuploidy and infertility.
Nat Struct Mol Biol
January 2025
Department of Reproductive Endocrinology, University Hospital Zurich, University of Zurich, Schlieren, Switzerland.
Want 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!