Equine oocyte-cumulus morphology as affected by follicular size.
Abstract: From the ovaries of 256 slaughtered mares a total of 1713 follicles were isolated from which 1641 (95.8%) oocytes were recovered (6.4/mare). A total of 564 follicles and oocytes were evaluated for the degree of vascularisation of the follicle wall, the appearance of the follicular fluid and the location and morphology of the cumulus-oocyte-complex. Follicles with a diameter of >10 mm displayed more numerous, well branched and more pronounced blood vessels than the smaller ones (4-10 mm diameter) and most of them contained clear, yellowish fluid with few granulosa cells. The percentage of oocytes with compact cumuli increased significantly with an increasing diameter of the follicle, being 233%, 43.9%, 55.6% and 64.2% (P<0.01) for the follicles with diameters of 4-10, 11-15, 16-20 and 21-35 mm, respectively. The percentage of oocytes attached to the follicle wall also increased with increasing follicle size, being 48.0%, 59.6%, 81.5% and 90.1% (P<0.01), respectively. On the contrary, the percentage of oocytes floating in the follicular fluid decreased with increasing follicle diameter, from 52.0% in the smallest follicles to 9.9% in the biggest ones. A significantly greater percentage of oocytes found on the follicular wall than in the follicular fluid had a compact cumulus (56.6 versus 21.3%; P<0.01). For in vitro culture were accepted 30.4%, 54.3%, 60.7% and 77.8% (P<0.01) of oocytes from the follicles with diameters of 4-10, 11-15, 16-20 and 21-35 mm, respectively. After culture for 28-40 h in TCM 199 medium, 90 of a total of 165 (54.5%) oocytes reached the metaphase II stage of maturation.
Publication Date: 1998-05-21 PubMed ID: 9593525DOI: 10.1111/j.2042-3306.1997.tb05097.xGoogle Scholar: Lookup
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- Comparative Study
- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
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The research study explores how follicular size impacts equine oocyte-cumulus morphology using ovaries from 256 slaughtered mares.
Research Methodology
- The researchers extracted a total of 1713 follicles from the ovaries of 256 slaughtered mares, recovering 1641 oocytes. This gave an average of 6.4 oocytes per mare.
- A total of 564 follicles and oocytes were selected for detailed examination. They were analyzed for vascularization of the follicle wall, the characteristics of the follicular fluid, and the cumulus-oocyte-complex’s position and structure.
Follicular Observations
- Follicles with a diameter greater than >10 mm displayed more abundant, well-branched and pronounced blood vessels than smaller follicles (4-10 mm diameter). They mostly contained a clear, yellowish fluid with fewer granulosa cells.
Oocyte Observations
- There was a significant increase in the percentage of oocytes with compact cumuli as the follicle diameter increased. The percentages were 23.3%, 43.9%, 55.6%, and 64.2% for follicles with diameters of 4-10, 11-15, 16-20, and 21-35 mm, respectively.
- A higher percentage of oocytes were attached to the follicle wall with increasing follicle size, whereas the percent of oocytes floating in the follicular fluid reduced with increasing follicle diameter.
- Oocytes found on the follicular wall had a significantly greater compact cumulus compared to those in the follicular fluid (56.6% versus 21.3%).
In-vitro Culture
- For in vitro culture, 30.4%, 54.3%, 60.7%, and 77.8% of oocytes from the follicles with diameters of 4-10, 11-15, 16-20 and 21-35 mm, respectively, were accepted.
- Following a culture period of 28-40 hours in TCM 199 medium, 90 out of a total of 165 oocytes (54.5%) reached the metaphase II stage of maturation.
Cite This Article
APA
Mlodawska W, Okólski A.
(1998).
Equine oocyte-cumulus morphology as affected by follicular size.
Equine Vet J Suppl(25), 38-42.
https://doi.org/10.1111/j.2042-3306.1997.tb05097.x Publication
Researcher Affiliations
- Department of Animal Reproduction, University of Agriculture, Kraków, Poland.
MeSH Terms
- Animals
- Female
- Fertilization in Vitro / methods
- Fertilization in Vitro / veterinary
- Horses / physiology
- Oocytes / cytology
- Oocytes / physiology
- Ovarian Follicle / cytology
- Ovarian Follicle / physiology
- Seasons
Citations
This article has been cited 1 times.- Abdoon AS, Abdel-Rahman HA, Shawki SM, Kandil OM, Fathalla SI. Influence of follicle size, methods of retrieval on oocytes yield and morphology in Egyptian Jennies ovaries with special reference to maturation rate in vitro. Vet Res Commun 2014 Dec;38(4):287-95.
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