Heat stress (HS) is a notable risk factor for female reproductive performance. In particular, impaired oocyte maturation was thought to contribute largely to the HS-induced reproductive dysfunctions. In this study, we confirmed that oocytes undergoing GVBD were much susceptible to HS, and thus compromising subsequent embryonic development. Using N-acetyl-l-cysteine (NAC), we found supplementation of a relatively high dose NAC during in vitro maturation, can protect oocytes from HS-induced complications, and thus rescuing impaired embryonic development. Further analysis indicated that mechanisms responsible for protecting GVBD oocytes from HS by NAC may include: (1) reversing disorganized spindle assembly and inhibited extracellular signal-regulated kinase (ERK) signaling; (2) correcting erroneous H3K27me3 modification and dysregulated expression of imprinted genes; (3) alleviating increased intraoocyte reactive oxygen species accumulation and apoptosis initiation. Our study, focusing on the oocyte meiotic maturation, may provide a safe and promising strategy for protecting reproductive sows under environmental hyperthermal conditions.
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http://dx.doi.org/10.1016/j.reprotox.2019.10.006 | DOI Listing |
Nucleic Acids Res
January 2025
MOE Key Laboratory of Biosystems Homeostasis and Protection, College of Life Sciences, Zhejiang University, No.866 Yuhangtang Road, 310058, Hangzhou, China.
Meiosis in mammalian oocytes is interrupted by a prolonged arrest at the germinal vesicle stage, during which oocytes have to repair DNA lesions to ensure genome integrity or otherwise undergo apoptosis. The FIRRM/FLIP-FIGNL1 complex dissociates RAD51 from the joint DNA molecules in both homologous recombination (HR) and DNA replication. However, as a type of non-meiotic, non-replicative cells, whether this RAD51-dismantling mechanism regulates genome integrity in oocytes remains elusive.
View Article and Find Full Text PDFJ Clin Med
January 2025
Gynecological Research Laboratory, Department of Obstetrics and Gynecology, Hillel Yaffe Medical Center, Hadera 3820302, Israel.
In this research, we retrospectively studied the influence of the IVF vs. the ICSI technique on embryo morphokinetics by means of a time-lapse incubator in fresh cycles. A total of 2645 treatment cycles resulting in ovum pick-up of 11,471 fertilized oocytes were included in the research from 2018 to 2022.
View Article and Find Full Text PDFCell Rep
January 2025
Genetics and Epigenetics Program, University of Texas MD Anderson Cancer Center and The University of Texas MD Anderson Cancer Center UTHealth Houston Graduate School of Biomedical Sciences, Houston, TX, USA; Department of Genetics, University of Texas MD Anderson Cancer Center and The University of Texas MD Anderson Cancer Center UTHealth Houston Graduate School of Biomedical Sciences, Houston, TX, USA. Electronic address:
ERK activity oscillates between sustained activation during oocyte formation and transient inactivation during oocyte maturation, fertilization, and early embryogenesis. Consequences of ectopic ERK activity upon oocyte maturation and in early embryogenesis are unknown. We show, in Caenorhabditis elegans, that ectopic ERK activity upon oocyte maturation (metaphase I oocytes) results in embryos with abnormalities in nuclear divisions leading to embryonic death.
View Article and Find Full Text PDFJ Assist Reprod Genet
January 2025
IVIRMA Global Research Alliance, RMA New Jersey, 140 Allen, Basking Ridge, NJ, 07920, USA.
Purpose: This study aimed to identify demographic and clinical factors associated with low maturation rates and to investigate if the rate of immature oocytes impacts the outcomes of mature sibling oocytes.
Methods: Women undergoing their first IVF-ICSI cycle between 2018 and 2022 at a fertility clinic were included. Cycles were classified into five groups according to the proportion of Metaphase II stage oocytes (MII): Null (0% MII, n = 46), Poor (1-25% MII, n = 44), Low (26-50% MII, n = 453), Acceptable (51-75% MII, n = 1641), and Optimal (76-100% MII, n = 2642).
Cochrane Database Syst Rev
January 2025
Institute of Education in Healthcare and Medical Sciences, University of Aberdeen, Aberdeen, UK.
Background: Gonadotropin-releasing hormone agonists (GnRHa) are commonly used in assisted reproduction technology (ART) cycles to prevent a luteinising hormone (LH) surge during controlled ovarian hyperstimulation (COH) prior to planned oocyte retrieval, thus optimising the chances of live birth. We compared the benefits and risks of the different GnRHa protocols used.
Objectives: To evaluate the effectiveness and safety of different GnRHa protocols used as adjuncts to COH in women undergoing ART.
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