Mammalian oocytes grow periodically after puberty thanks to the dialogue with their niche in the follicle. This communication between somatic and germ cells promotes the accumulation, inside the oocyte, of maternal RNAs, proteins and other molecules that will sustain the two gamete divisions and early embryo development up to its implantation. In order to preserve their stock of maternal products, oocytes from all species divide twice minimizing the volume of their daughter cells to their own benefit. For this, they undergo asymmetric divisions in size where one main objective is to locate the division spindle with its chromosomes off-centred. In this chapter, we will review how this main objective is reached with an emphasis on the role of actin microfilaments in this process in mouse oocytes, the most studied example in mammals. This chapter is subdivided into three parts: I-General features of asymmetric divisions in mouse oocytes, II-Mechanism of chromosome positioning by actin in mouse oocytes and III-Switch from asymmetric to symmetric division at the oocyte-to-embryo transition.
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http://dx.doi.org/10.1007/978-3-319-53150-2_13 | DOI Listing |
Life Med
October 2024
State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100101, China.
The ovary plays a crucial role in the reproductive system of female mammals by producing mature oocytes through folliculogenesis. Non-human model organisms are extensively utilized in research on human ovarian biology, thus necessitating the investigation of conservation and divergence in molecular mechanisms across species. In this study, we employed integrative single-cell analysis of transcriptome and chromatin accessibility to identify the evolutionary conservation and divergence patterns of ovaries among humans, monkeys, mice, rats, and rabbits.
View Article and Find Full Text PDFLife Med
February 2024
Institute of Reproductive Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
Ovarian aging is mainly characterized by a progressive decline in oocyte quantity and quality, which ultimately leads to female infertility. Various therapies have been established to cope with ovarian aging, among which exosome-based therapy is considered a promising strategy that can benefit ovarian functions via multiple pathways. Here, we isolated and characterized exosomes derived from ovarian follicular fluid and profiled the differential expression patterns of noncoding exosomal RNAs in young and aged women.
View Article and Find Full Text PDFRedox Biol
January 2025
Department of Reproductive Medicine, Jinling Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, Jiangsu, 210002, China; State Key Laboratory of Reproductive Medicine and Offspring Health, Nanjing Medical University, Nanjing, Jiangsu, 211166, China; Department of Reproductive Medicine, Affiliated Jinling Hospital, The First School of Clinical Medicine, Southern Medical University, Nanjing, 210002, China. Electronic address:
Oocyte aging is closely related to a decline in female fertility, accompanied by increased reactive oxygen species levels and changes in protein posttranslational modifications. However, the role of protein palmitoylation in oocyte aging has not been investigated. In the present study, a new association between redox and palmitoylation in aging oocytes was found.
View Article and Find Full Text PDFCell
January 2025
Institute of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, CAS Key Laboratory of Primate Neurobiology, State Key Laboratory of Neuroscience, Chinese Academy of Sciences, Shanghai 200031, China; Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology, Shanghai 200031, China. Electronic address:
Understanding mammalian preimplantation development, particularly in humans, at the proteomic level remains limited. Here, we applied our comprehensive solution of ultrasensitive proteomic technology to measure the proteomic profiles of oocytes and early embryos and identified nearly 8,000 proteins in humans and over 6,300 proteins in mice. We observed distinct proteomic dynamics before and around zygotic genome activation (ZGA) between the two species.
View Article and Find Full Text PDFTheriogenology
January 2025
College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai'an City, 271018, PR China. Electronic address:
Post-maturation oocyte aging (PMOA) is known to significantly impair the developmental potential of oocytes; however, comprehensive studies on ovine PMOA remain limited. In mice, cumulus cells (CCs) accelerate oocyte aging by releasing cytokines, but the roles of CCs and cytokines in PMOA of domestic animals are poorly understood. This study aimed to elucidate the involvement of CCs and tumor necrosis factor (TNF)-α in the PMOA of ovine oocytes.
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