The binding of a spermatozoon to the zona pellucida is the first step in fertilization. The number of spermatozoa bound to a zona pellucida may reflect the functional status of both the oocyte and spermatozoa. The aim of the present study was to determine whether the stage of maturation of the equine oocyte affects the capacity of the zona pellucida to bind with spermatozoa. Cumulus-oocyte complexes (COCs) were collected from the ovaries of mares from abattoirs or were obtained in vivo by ultrasound-guided follicular aspiration. Oocytes were inseminated directly after collection or after 30 h of in vitro maturation (IVM) with semen from the same ejaculate. The results indicate that the immature equine oocytes collected from abattoirs and inseminated directly after collection bound fewer spermatozoa than did mature (metaphase I or II) oocytes inseminated after 30 h of IVM. A similar correlation was observed with the oocytes collected in vivo. The mean number of spermatozoa bound by mature oocytes collected from preovulatory follicles and inseminated directly after collection was 324 +/- 29, whereas the mean number of spermatozoa bound by immature oocytes from nonpreovulatory follicles inseminated without maturation was 222 +/- 26 (P < 0.05). This difference was not observed in the oocytes inseminated after maturation. It is postulated that immature equine oocytes bind fewer spermatozoa than do oocytes matured either in vivo or in vitro.
Download full-text PDF |
Source |
|---|
Publication Analysis
Top Keywords
Similar Publications
Sperm vitrification in horses and donkeys.
J Equine Vet Sci
January 2025
Veterinary Reproduction Group, Faculty of Veterinary Medicine, University of Cordoba, Spain. Electronic address:
Sperm vitrification is an alternative freezing method, which includes high cooling rates and non-permeable cryoprotectants agents. The first attempt in equids was using the spheres technique by directly dropping small volumes of the sperm into liquid nitrogen. Later, vitrification was developed using 0.
View Article and Find Full Text PDFFactors influencing oocyte recovery during ultrasound-guided follicle aspiration in mares: A postmortem study.
Theriogenology
December 2024
Equine Fertility Group, Facultad de Veterinaria, Universidad Cardenal Herrera-CEU, CEU Universities, Alfara Del Patriarca, Spain. Electronic address:
The objectives of this study were to investigate the influence of different OPU variables (vacuum and injection pressures during follicle aspiration and flushing, needle twisting to scrape follicles, number of follicle flushes and type of flushing media) on oocyte recovery rate (ORR) and morphology. Overall, 120 postmortem excised ovaries were processed in 62 replicates (1.9 ± 0.
View Article and Find Full Text PDFFluctuations of antimüllerian hormone, ovarian follicular reserve, and antioxidant status throughout the estrous cycle in aged mares.
Open Vet J
November 2024
Theriogenology Department, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt.
Background: Senility influences fertility in women and companion animals, especially horses.
Aim: This study aimed to investigate the effect of aging in horses on the daily changes in the dominant follicle (DF) dynamics and hemodynamics, antimüllerian hormone (AMH), enzymes, antioxidants, and ovarian hormones during the estrous cycle.
Methods: Ovaries of old mares ( = 5, age >20 years) and young native mares ( = 6, age <10 years) were scanned during 6 different estrous cycles from March 2022 to August 2023 with Doppler ultrasound.
Immunohistochemical assessment of ERM proteins (ezrin, radixin, moesin) in the ovaries of different species.
Tissue Cell
November 2024
Department of Biomedical Sciences and Pathobiology, Center of Pathobiology, University of Veterinary Medicine, Vienna, Austria; VetCore Facility for Research, University of Veterinary Medicine, Vienna, Austria. Electronic address:
Article Synopsis
- Ezrin, radixin, and moesin (ERM) proteins connect membrane proteins to the actin cytoskeleton, but their role in healthy reproductive tissues is under-researched.
- A study used immunohistochemistry to analyze the distribution of these proteins in ovaries from various animal species, including mice, dogs, and pigs.
- Findings revealed differences in localization and expression of ERM proteins across species and ovarian structures, which could enhance our understanding of their physiological roles in female reproduction.
Oocyte holding and in vitro maturation duration between 28 and 34 hours do not affect equine OPU-ICSI outcomes.
Theriogenology
February 2025
Department of Internal Medicine, Reproduction and Population Medicine, Ghent University, Merelbeke, Belgium.
Previous studies in the horse highlight the potential benefit of prolonged in vitro maturation (IVM) (34 h) compared to short IVM (24 h) with or without prior oocyte holding, but little is known about the optimal IVM duration within this interval. To determine the effect of oocyte holding and duration of IVM ranged between 28 and 34 h on nuclear maturation, cleavage, blastocyst formation, and pregnancy rates, a retrospective study was performed in an equine clinical OPU-ICSI setting. The study included data of 2114 aspirated oocytes from 201 OPU-ICSI sessions.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!