Morphology and location of attached follicular cumulus-oocyte complexes in horses, cattle and llamas.
Abstract: Morphology and location of the attached cumulus-oocyte complex (COC) were studied in slaughter-house ovaries in horses (49 follicles, 9 to 44 mm), cattle (68 follicles, 6 to 18 mm), and llamas (38 follicles, 3 to 14 mm). The expected point of ovulation was marked, using the ovulation fossa in mares and the center of the projecting follicular surface in cattle and llamas. A follicle was dissected from an ovary, and tissue was removed from the follicle until the COC became visible by transillumination. However, most llama follicles protruded prominently from the ovarian surface so that dissection was not required to locate the COC. The COC was more readily recognized from the external follicular surface in mares and llamas than in cattle, primarily because of a dark oocyte. Compact COC's projected into the antrum with a smooth dome-shape in horses. The COC's in cattle were also dome-shaped but were more irregular and a few contained prominent processes. The mean diameter of the isolated follicle was calculated from 3 planes, except that in llamas the follicles were spherical so that the 3 dimensions were identical. The angle between a straight line connecting the expected ovulation site and the opposite pole and a straight line from the ovulation site to the COC was defined as the COC-location angle. This angle was chosen because it is unaltered by size of a sphere (45 degrees for a COC at the equator). The mean (+/-SEM) COC-location angle differed (P < 0.01) among horses (39.9 +/- 3.3), cattle (50.0 +/- 2.5), and llamas (64.8 +/- 2.1). In mares, the locations of the COC's did not differ from equality between follicular hemispheres, but in cattle and llamas the COC's were located with greater frequency (P < 0.05) in the hemisphere containing the expected ovulation site (cattle, 65%; llamas, 91%).
Publication Date: 1995-02-01 PubMed ID: 16727644DOI: 10.1016/0093-691x(94)00058-3Google Scholar: Lookup
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Summary
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The research carries out a comparative study on the morphology and location of cumulus-oocyte complex (COC) in the ovaries of horses, cattle, and llamas, with findings revealing different characteristics and positioning across the three species.
Research Methodology
- The researchers conducted their study on ovaries obtained from slaughterhouses. They examined 49 horse follicles sized 9 to 44 mm, 68 cattle follicles sized 6 to 18 mm, and 38 llama follicles sized 3 to 14 mm.
- They marked the expected point of ovulation using the ovulation fossa for horses and the center of the projecting follicular surface for cattle and llamas.
- Dissection of a follicle from an ovary was performed and tissue removed until the COC was visible through transillumination. Most llama follicles protruded from the ovarian surface, making dissection unnecessary.
Results and Findings
- It was observed that the external follicular surface in mares and llamas showed a COC more visibly than in cattle, likely due to the presence of a dark oocyte.
- The COCs in horses were compact, with a smooth dome-shape, projecting into the antrum. In comparison, the COCs in cattle, while also dome-shaped, were irregular and sometimes had prominent processes.
- The average diameter of the isolated follicle was calculated from three dimensions. In the case of llamas, the follicles were spherical, making these dimensions identical.
Analysis of Cumulus-Oocyte-Complex (COC) Location
- The location of the COCs was determined by measuring an angle from the expected ovulation site to the COC and the opposite pole. This measure is important as it is unchangeable by the size of a sphere. This angle is referred to as the COC-location angle.
- Different COC-location angles were found amongst horses, cattle, and llamas with averages of 39.9, 50.0, and 64.8 respectively.
- In horses, the locations of COCs did not significantly differ between follicular hemispheres. However, in cattle and llamas, COCs were more frequently found in the hemisphere containing the expected ovulation site.
Cite This Article
APA
Del Campo MR, Del Campo CH, Mapletoft RJ, Ginther OJ.
(1995).
Morphology and location of attached follicular cumulus-oocyte complexes in horses, cattle and llamas.
Theriogenology, 43(3), 533-542.
https://doi.org/10.1016/0093-691x(94)00058-3 Publication
Researcher Affiliations
- Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada, 57N OWO.
Citations
This article has been cited 2 times.- Landeo L, Zuñiga M, Gastelu T, Artica M, Ruiz J, Silva M, Ratto MH. Oocyte Quality, In Vitro Fertilization and Embryo Development of Alpaca Oocytes Collected by Ultrasound-Guided Follicular Aspiration or from Slaughterhouse Ovaries. Animals (Basel) 2022 Apr 25;12(9).
- Ishak GM, Bashir ST, Dutra GA, Gastal GDA, Gastal MO, Cavinder CA, Feugang JM, Gastal EL. In vivo antral follicle wall biopsy: a new research technique to study ovarian function at the cellular and molecular levels. Reprod Biol Endocrinol 2018 Jul 28;16(1):71.
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