Meiosis produces haploid gametes by accurately reducing chromosome ploidy through one round of DNA replication and two subsequent rounds of chromosome segregation and cell division. The cell divisions of female meiosis are highly asymmetric and give rise to a large egg and two very small polar bodies that do not contribute to development. These asymmetric divisions are driven by meiotic spindles that are small relative to the size of the egg and have one pole juxtaposed against the cell cortex to promote polar body extrusion. An additional unique feature of female meiosis is that fertilization occurs before extrusion of the second polar body in nearly all animal species. Thus sperm-derived chromosomes are present in the egg during female meiosis. Here, we explore the idea that the asymmetry of female meiosis spatially separates the sperm from the meiotic spindle to prevent detrimental interactions between the spindle and the paternal chromosomes.
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http://dx.doi.org/10.1080/15384101.2018.1431495 | DOI Listing |
Proc Natl Acad Sci U S A
January 2025
HHMI, University of California, Davis, CA 95616.
During meiosis, each pair of homologous chromosomes becomes connected by at least one crossover, as required for accurate segregation, and adjacent crossovers are widely separated thereby limiting total numbers. In coarsening models, this crossover patterning results from nascent recombination sites competing to accrue a limiting pro-crossover RING-domain protein (COR) that diffuses between synapsed chromosomes. Here, we delineate the localization dynamics of three mammalian CORs in the mouse and determine their interdependencies.
View Article and Find Full Text PDFCell Commun Signal
January 2025
Laboratory of Theriogenology, College of Veterinary Medicine, Chungnam National University, Daejeon, 34134, Republic of Korea.
Background: Although the Notch signaling pathway is known to play an important role in ovarian follicle development in mammals, whether it is involved in oocyte maturation remains unclear. Therefore, this study was performed to elucidate the existence and role of the Notch signaling pathway during oocyte maturation in a porcine model.
Methods: Reverse transcription-polymerase chain reaction (RT-PCR) and immunocytochemical assays were used to determine the existence of Notch signaling pathway-related transcripts and proteins in porcine cumulus-oocyte complexes (COCs).
Reprod Toxicol
December 2024
Department of Basic Medicine, School of Medicine, Xiamen University, Xiamen, Fujian, 361102, China. Electronic address:
Per- and polyfluoroalkyl substances (PFAS) are synthetic perfluorinated compounds known for their persistence in the environment and reproduction toxicity. PFAS, perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), have been identified in the follicular fluid of infertile women. However, the specific of PFOA and PFOS mixture on oocyte quality and female fertility remain unclear.
View Article and Find Full Text PDFEur J Med Res
December 2024
School of Medicine, Iran University of Medical Sciences, Tehran, Iran.
Infertility is a prevalent problem among 10% of people within their reproductive years. Sometimes, even advanced treatment options like assisted reproduction technology have the potential to result in failed implantation. Because of the expected changes in gene expression during both in vitro and in vivo fertilization processes, these methods of assisting fertility have also been associated with undesirable pregnancy outcomes related to infertility.
View Article and Find Full Text PDFCell Biosci
December 2024
Assisted Reproduction Unit, Department of Obstetrics and Gynecology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, 310016, China.
Background: Oocyte maturation defect (OMD) and early embryonic arrest result in female infertility. Previous studies have linked biallelic mutations in the PATL2 gene to OMD, yet the underlying mechanism remains largely unknown.
Results: This study uncovers three novel mutations (c.
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