The presence of cyclic adenosine monophosphate (cAMP) has been considered to be a fundamental factor in ensuring meiotic arrest prior to ovulation. cAMP is regarded as a key molecule in the regulation of oocyte maturation. However, it has been reported that increased levels of intracellular cAMP can result in abnormal cytokinesis, with some MI oocytes leading to symmetrically cleaved 2-cell MII oocytes. Consequently, we aimed to investigate the effects of elevated intracellular cAMP levels on abnormal cytokinesis and oocyte maturation during the meiosis of mouse oocytes. This study found that a high concentration of isobutylmethylxanthine (IBMX) also caused chromatin/chromosomes aggregation (AC) after the first meiosis. The rates of AC increased the greater the concentration of IBMX. In addition, AC formation was found to be reversible, showing that the re-formation of the spindle chromosome complex was possible after the IBMX was removed. In human oocytes, the chromosomes aggregate after the germinal vesicle breakdown and following the first and second polar body extrusions (the AC phase), while mouse oocytes do not have this AC phase. The results of our current study may indicate that the AC phase in human oocytes could be related to elevated levels of intracytoplasmic cAMP.
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http://dx.doi.org/10.1080/19396368.2024.2368116 | DOI Listing |
Nat Struct Mol Biol
January 2025
Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing, China.
Up to an estimated 10% of women experience miscarriage in their lifetimes. Embryonic aneuploidy is a leading cause for miscarriage, infertility and congenital defects. Here we identify variants of ELL3, a gene encoding a transcription elongation factor, in couples who experienced consecutive early miscarriages due to embryonic aneuploidy.
View Article and Find Full Text PDFJ Hazard Mater
January 2025
Centre of Reproductive Medicine, Department of Obstetrics and Gynaecology, Shengjing Hospital of China Medical University, No. 39 Huaxiang Road, Tiexi District, Shenyang, Liaoning 110022, PR China; Key Laboratory of Reproductive Dysfunction Disease and Fertility Remodelling of Liaoning Province, Shenyang, Liaoning 110022, PR China. Electronic address:
Sulfur dioxide (SO) is a contributor to air pollution. Human evidence has demonstrated an association between SO exposure and diminished ovarian reserve. The toxicity of SO is mainly attributed to its derivatives, bisulfite and sulfite, which have a variety of adverse effects on both human health and the environment, yet have been widely used as additives in food processing and transportation.
View Article and Find Full Text PDFTransl Androl Urol
December 2024
Center for Reproductive Medicine, Affiliated Hospital of Nantong University, Nantong, China.
Background: Para-phenylenediamine (PPD) is a crystalline solid that belongs to the aromatic amine group, widely used in the manufacturing of various dyes. PPD exhibits toxic effects on female hormone stability, ovarian function, and embryo development. Although studies have shown that PPD exposure can damage oocyte quality in female mice, research on its effects on male reproductive capability, particularly on human sperm quality and function, is limited.
View Article and Find Full Text PDFSci China Life Sci
January 2025
College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China.
Mitochondrial Rho-GTPase 1 (MIRO1) is an outer mitochondrial membrane protein which regulates mitochondrial transport and mitophagy in mitosis. In present study, we reported the crucial roles of MIRO1 in mammalian oocyte meiosis and its potential relationship with aging. We found that MIRO1 expressed in mouse and porcine oocytes, and its expression decreased in aged mice.
View Article and Find Full Text PDFBr J Pharmacol
January 2025
Department of Physiology and Pharmacology, School of Medicine, Tel Aviv University, Tel Aviv, Israel.
Background And Purpose: The antiepileptic drug ethosuximide (ETX) suppresses epileptiform activity in a mouse model of GNB1 syndrome, caused by mutations in Gβ protein, likely through the inhibition of G-protein gated K (GIRK) channels. Here, we investigated the mechanism of ETX inhibition (block) of different GIRKs.
Experimental Approach: We studied ETX inhibition of GIRK channels expressed in Xenopus oocytes with or without their physiological activator, the G protein subunit dimer Gβγ.
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