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Centromeres are the chromosomal domains, where the kinetochore protein complex is formed, mediating proper segregation of chromosomes during cell division. Although the function of centromeres has remained conserved during evolution, centromeric DNA is highly variable, even in closely related species. In addition, the composition of the kinetochore complexes varies among organisms. Therefore, it is assumed that the centromeric position is determined epigenetically, and the centromeric histone H3 (CENH3) serves as an epigenetic marker. The loading of CENH3 onto centromeres depends on centromere-licensing factors, chaperones, and transcription of centromeric repeats. Several proteins that regulate CENH3 loading and kinetochore assembly interact with the centromeric transcripts and DNA in a sequence-independent manner. However, the functional aspects of these interactions are not fully understood. This review discusses the variability of centromeric sequences in different organisms and the regulation of their transcription through the RNA Pol II and RNAi machinery. The data suggest that the interaction of proteins involved in CENH3 loading and kinetochore assembly with centromeric DNA and transcripts plays a role in centromere, and possibly neocentromere, formation in a sequence-independent manner.
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http://dx.doi.org/10.1111/tpj.16445 | DOI Listing |
Am J Obstet Gynecol
August 2025
State Key Laboratory of Reproductive Medicine and Offspring Health, Nanjing Medical University, Nanjing, China; Center of Reproduction and Genetics, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou Municipal Hospital, Gusu School, Nanjing Medical University, Suzhou, China; Innova
Background: During mammalian oocyte meiosis, accurate chromosome segregation critically depends on precise regulation of kinetochore-microtubule (K-MT) attachments, a process monitored by the spindle assembly checkpoint (SAC). While CENP-F has been well characterized as a kinetochore-associated protein that stabilizes K-MT connections during mitosis, its functional mechanisms during meiosis remain poorly understood. In particular, there is still controversy over whether farnesylation modification governs localization and functionality of CENP-F.
View Article and Find Full Text PDFFront Cell Dev Biol
August 2025
Key Laboratory of Local Livestock and Poultry Genetical Resource Conservation and Breeding of Anhui Province, College of Animal Science and Technology, Anhui Agricultural University, Hefei, China.
Introduction: Mre11 is a multisubunit nuclease involved in DNA repair, and its dysfunction often causes DNA damage sensitivity, genomic instability, telomere shortening, and aberrant meiosis. However, the specific roles of Mre11 in porcine oocyte meiosis remain unclear.
Methods: In this study, porcine oocytes were treated with the Mre11-specific inhibitor mirin to investigate the function of Mre11 during meiotic maturation.
EMBO Rep
August 2025
Laboratory for Chromosome Segregation, RIKEN Center for Biosystems Dynamics Research (BDR), Kobe, Japan.
Bipolar spindle assembly and chromosome biorientation are prerequisites for chromosome segregation during cell division. The kinesin motor KIF11 (also widely known as Eg5) drives spindle bipolarization by sliding antiparallel microtubules bidirectionally, elongating a spherical spindle into a bipolar-shaped structure in acentrosomal oocytes. During meiosis I, this process stretches homologous chromosome pairs, establishing chromosome biorientation at the spindle equator.
View Article and Find Full Text PDFNat Commun
August 2025
McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin-Madison, Madison, WI, USA.
The kinetochore, an intricate macromolecular protein complex located on chromosomes, plays a pivotal role in orchestrating chromosome segregation. It functions as a versatile platform for microtubule assembly, diligently monitors microtubule binding fidelity, and acts as a force coupler. Comprising over 100 distinct proteins, many of which exist in multiple copies, the kinetochore's composition dynamically changes throughout the cell cycle, responding to specific timing and conditions.
View Article and Find Full Text PDFFASEB J
August 2025
Department of Basic Medicine, School of Medicine, Xiamen University, Xiamen, Fujian, China.
The proper assembly and migration of the spindle and the correct segregation of the chromosomes play a crucial role in oocyte quality. In somatic cells, Psrc1 regulates spindle dynamics and mitotic progression; however, its functions in oocyte meiosis have not been fully elucidated. This study aims to elucidate the functions of Psrc1 in mouse oocyte meiosis.
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