Meiotic competence in horse oocytes: interactions among chromatin configuration, follicle size, cumulus morphology, and season.
Abstract: Horse oocytes were collected from an abattoir over a 15-mo period. After classification of follicle size and cumulus morphology, oocytes were either fixed immediately (0 h) or matured in vitro (24 h). There was no effect of season on the number of antral follicles present on the ovaries, or on oocyte maturation rate for any class of oocyte. The proportion of oocytes having condensed chromatin at 0 h increased with increasing follicle size. The oocyte maturation rate also increased with follicle size, and for follicles </= 20-mm diameter, was higher for oocytes initially having expanded cumuli than for those having compact cumuli. The maturation rate was strongly correlated (r(2) = 0.92) with the proportion of oocytes having condensed chromatin at 0 h. Oocytes with diffuse chromatin were found essentially only in follicles </= 20-mm diameter that yielded compact granulosa, indicating follicle viability. Presence of diffuse chromatin was inversely related to maturation rate. We conclude that the major signal for chromatin condensation, and thus acquisition of meiotic competence, occurs in viable follicles after 20-mm diameter in the horse. Condensation of chromatin in oocytes in smaller apparently viable follicles, while associated with acquisition of meiotic competence, may represent a pre-atretic change.
Publication Date: 2000-04-25 PubMed ID: 10775193DOI: 10.1095/biolreprod62.5.1402Google Scholar: Lookup
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- Journal Article
- Research Support
- U.S. Gov't
- Non-P.H.S.
Summary
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This research is about how chromatin configuration, follicle size, cumulus morphology, and season affect the meiotic capability of horse oocytes, which was studied over a 15-month period. The study found a firm correlation between the oocyte maturation rate and the proportion of oocytes with condensed chromatin.
Methodology
- The researchers collected horse oocytes from an abattoir over a period of 15 months.
- After classification according to follicle size and cumulus morphology, the oocytes were either fixed immediately (0 h) or matured in an in vitro environment for a 24-hour period.
- The researchers then studied the effects of different variables such as season, follicle size, and cumulus morphology on the number of antral follicles present on the ovaries, the rate of oocyte maturation, and the chromatin configuration within the oocytes.
Key Findings
- Season had no apparent influence on the number of antral follicles present on the ovaries or the rate of oocyte maturation for any category of oocyte.
- The proportion of oocytes having condensed chromatin at 0 h increased with the size of the follicle.
- The maturation rate of the oocytes also increased with the follicle size. For follicles with a diameter of less than or equal to 20 mm, the maturation rate was higher for oocytes having expanded cumuli than those with compact cumuli.
- Oocytes with diffuse chromatin were essentially found only in follicles with a diameter of less than or equal to 20 mm that yielded compact granulosa. This indicates the viability of the follicle.
Conclusions
- The research concluded that the major signal for chromatin condensation, and thus the acquisition of meiotic competence, occurs in viable follicles after they reach a diameter of 20 mm in horses.
- While associated with the acquisition of meiotic competence, condensation of chromatin in oocytes in smaller viable follicles could represent a pre-atretic (follicle degenerating) change.
Cite This Article
APA
Hinrichs K, Schmidt AL.
(2000).
Meiotic competence in horse oocytes: interactions among chromatin configuration, follicle size, cumulus morphology, and season.
Biol Reprod, 62(5), 1402-1408.
https://doi.org/10.1095/biolreprod62.5.1402 Publication
Researcher Affiliations
- Tufts University School of Veterinary Medicine, North Grafton, Massachusetts 01536, USA. khinrichs@cvm.tamu.edu
MeSH Terms
- Animals
- Cell Size
- Chromatin / ultrastructure
- Female
- Horses
- Meiosis
- Oocytes / cytology
- Ovarian Follicle / cytology
- Seasons
Citations
This article has been cited 13 times.- Hedia M, Leroy JLMR, Govaere J, Van Soom A, Smits K. Lipid metabolites, interleukin-6 and oxidative stress markers in follicular fluid and their association with serum concentrations in mares.. Vet Res Commun 2023 Apr 14;.
- Orsolini MF, Meyers SA, Dini P. An Update on Semen Physiology, Technologies, and Selection Techniques for the Advancement of In Vitro Equine Embryo Production: Section II.. Animals (Basel) 2021 Nov 20;11(11).
- Serra E, Gadau SD, Leoni GG, Naitana S, Succu S. Seasonal Effect on Developmental Competence, Oxidative Status and Tubulin Assessment of Prepubertal Ovine Oocyte.. Animals (Basel) 2021 Jun 24;11(7).
- Bogolyubova I, Bogolyubov D. Heterochromatin Morphodynamics in Late Oogenesis and Early Embryogenesis of Mammals.. Cells 2020 Jun 19;9(6).
- Grady ST, Watts AE, Thompson JA, Penedo MCT, Konganti K, Hinrichs K. Effect of intra-ovarian injection of mesenchymal stem cells in aged mares.. J Assist Reprod Genet 2019 Mar;36(3):543-556.
- Abdel-Salam Z, Harith MA. Laser researches on livestock semen and oocytes: A brief review.. J Adv Res 2015 May;6(3):311-7.
- Kołowerzo-Lubnau A, Niedojadło J, Świdziński M, Bednarska-Kozakiewicz E, Smoliński DJ. Transcriptional activity in diplotene larch microsporocytes, with emphasis on the diffuse stage.. PLoS One 2015;10(2):e0117337.
- Revelli A, Martiny G, Delle Piane L, Benedetto C, Rinaudo P, Tur-Kaspa I. A critical review of bi-dimensional and three-dimensional ultrasound techniques to monitor follicle growth: do they help improving IVF outcome?. Reprod Biol Endocrinol 2014 Nov 24;12:107.
- Martino NA, Dell'Aquila ME, Filioli Uranio M, Rutigliano L, Nicassio M, Lacalandra GM, Hinrichs K. Effect of holding equine oocytes in meiosis inhibitor-free medium before in vitro maturation and of holding temperature on meiotic suppression and mitochondrial energy/redox potential.. Reprod Biol Endocrinol 2014 Oct 11;12:99.
- 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.
- Luciano AM, Lodde V, Franciosi F, Tessaro I, Corbani D, Modina S. Large-scale chromatin morpho-functional changes during mammalian oocyte growth and differentiation.. Eur J Histochem 2012 Aug 10;56(3):e37.
- Ambruosi B, Uranio MF, Sardanelli AM, Pocar P, Martino NA, Paternoster MS, Amati F, Dell'Aquila ME. In vitro acute exposure to DEHP affects oocyte meiotic maturation, energy and oxidative stress parameters in a large animal model.. PLoS One 2011;6(11):e27452.
- Lange Consiglio A, Dell'Aquila ME, Fiandanese N, Ambruosi B, Cho YS, Bosi G, Arrighi S, Lacalandra GM, Cremonesi F. Effects of leptin on in vitro maturation, fertilization and embryonic cleavage after ICSI and early developmental expression of leptin (Ob) and leptin receptor (ObR) proteins in the horse.. Reprod Biol Endocrinol 2009 Oct 16;7:113.
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