After ovulation, the fertile life of oocytes is short. In the present study, the fertile life of oocytes was studied in relation to the resumption of meiosis. Early on the day of pro-oestrus, meiotic resumption was advanced in rats by a brief infusion of LH; ovulation was induced 8 h later by Ovalyse, a GnRH analogue; rats were mated 13 h after receiving Ovalyse, that is at about the time of ovulation. Rats in which meiosis was not advanced were injected with Ovalyse and mated at various intervals after ovulation. Rats were killed 13 h after mating or on day 20 of pregnancy. In rats in which meiosis was not advanced that were mated around ovulation, fetal survival was about 90%. In rats with meiosis advanced by 8 h and mated around ovulation, only 44% of the ovulated oocytes with advanced meiosis developed into healthy fetuses; mortality before and after implantation was 37 and 19%, respectively. Rats in which meiosis was not advanced that were mated 8-9 h after ovulation had similar fetal survival and similar mortality before and after implantation. Thus ageing of the oocyte may occur either before, or after, ovulation. Preovulatory ageing is related to the resumption of meiosis.
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http://dx.doi.org/10.1530/jrf.0.1000065 | DOI Listing |
Curr Protoc
December 2024
Department of Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas.
These protocols describe a detailed method to determine the DNA damage and F-actin and microtubule defects of metaphase II oocytes caused by hexavalent chromium, Cr(VI), an endocrine disrupting chemical (EDC). The protocol provides systematic steps to determine protein expression encoded by pluripotency proteins such as Oct4, Nanog, and Cdx2 during early embryonic development. Occupational or environmental exposure to EDCs has significantly increased infertility in both men and women.
View Article and Find Full Text PDFFront Cell Dev Biol
November 2024
Laboratorio de Biología de la Reproducción, Instituto Nacional de Pediatría, Mexico City, Mexico.
Background: Congenital hypothyroidism (CH) is a pathology that affects various organs, including the testicles. The mechanisms by which this condition alters fertility is unknown. This study aimed at determining if experimental CH affects gonocyte differentiation and arrests meiosis; and the possible role of the Sertoli cell (SC) in this condition.
View Article and Find Full Text PDFInt J Mol Sci
October 2024
Pathobiology and Extracellular Vesicles Research Group, School of Life Sciences, University of Westminster, London W1W 6XH, UK.
Gene
January 2025
Medical Research Center, Fujian Maternity and Child Health Hospital, Fuzhou, Fujian 350001, China; College of Clinical Medicine for Obstetrics & Gynecology and Pediatrics, Fujian Medical University, Fuzhou, Fujian 350122, China; Fujian Key Laboratory of Women and Children's Critical Diseases Research, Fujian Maternity and Child Health Hospital, Fuzhou, Fujian 350001, China. Electronic address:
C-terminal kinesin motor KIFC1 is increasingly concerned with an essential role in germ cell development. During the spermatogenesis of mice, rats, and crustaceans, KIFC1 functions in regulating meiotic chromosome separation, acrosome vesicle transportation, and nuclear morphology maintenance. The expression pattern of KIFC1 is conservatively concentrated at the acrosome and nucleus of haploid sperm cells.
View Article and Find Full Text PDFMethods Mol Biol
August 2024
Magee-Womens Research Institute, Department of Obstetrics, Gynecology & Reproductive Sciences, University of Pittsburgh, Pittsburgh, PA, USA.
Recently, we reported that, in the naked mole-rat (Heterocephalus glaber) ovary, there is mitotic expansion of the primordial germ cells (PGCs), and the initiation of the meiotic program occurs postnatally. This is opposite to almost all other mammals, including humans and mice, whose reproductive cycle begins very early in development. In both mouse and human, the ovaries become populated with PGCs in utero; these PGCs will later generate the oogonia.
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