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The mare: a 1000-pound guinea pig for study of the ovulatory follicular wave in women.
Abstract: The mare is a good comparative model for study of ovarian follicles in women, owing to striking similarities in follicular waves and the mechanism for selection of a dominant follicle. Commonality in follicle dynamics between mares and women include: (1) a ratio of 2.2:1 (mare:woman) in diameter of the largest follicle at wave emergence when the wave-stimulating FSH surge reaches maximum, in diameter increase of the two largest follicles between emergence and the beginning of deviation between the future dominant and subordinate follicles, in diameter of each of the two largest follicles at the beginning of deviation, and in maximum diameter of the preovulatory follicle; (2) emergence of the future ovulatory follicle before the largest subordinate follicle; (3) a mean interval of 1 day between emergence of individual follicles of the wave; (4) percentage increase in diameter of follicles for the 3 days before deviation; (5) deviation 3 or 4 days after emergence; (6) 25% incidence of a major anovulatory follicular wave emerging before the ovulatory wave; (7) 40% incidence of a predeviation follicle preceding the ovulatory wave; (8) small but significant increase in estradiol and LH before deviation; (9) cooperative roles of FSH and insulin-like growth factor 1 and its proteases in the deviation process; (10) age-related effects on the follicles and oocytes; (11) approximate 37-hour interval between administration of hCG and ovulation; and (12) similar gray-scale and color-Doppler ultrasound changes in the preovulatory follicle. In conclusion, the mare may be the premier nonprimate model for study of follicle dynamics in women.
Copyright © 2012 Elsevier Inc. All rights reserved.
Publication Date: 2011-11-23 PubMed ID: 22115815DOI: 10.1016/j.theriogenology.2011.09.025Google Scholar: Lookup The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Comparative Study
- Journal Article
- Research Support
- Non-U.S. Gov't
- Review
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
This research article focuses on the striking similarities between the ovarian follicles of mares and women, making mares a valuable model for studying these follicles in women.
Comparison between Mare and Women’s Ovarian Follicular Activities
The researchers highlight several reasons why the mare can serve as a suitable comparative model for studying ovarian follicles in women:
- The diameter of ovarian follicles in mares and women shows a particular ratio related to various stages of follicle development. When the follicle-stimulating hormone (FSH) surge reaches its maximum, the largest follicle at wave emergence has a diameter ratio of 2.2:1 (mare: woman). This ratio is also observed in the diameter increase of the two largest follicles between emergence and the start of deviation, the beginning of deviation itself, and the maximum diameter of the preovulatory follicle.
- The future ovulatory follicle emerges before the largest subordinate follicle in both species.
- There is a mean interval of one day between the emergence of individual follicles of the wave.
- Three days prior to the deviation point, follicles in both mares and women show a significant increase in diameter.
- Three or four days after the follicular wave emergence, the deviation process begins.
- There’s a 25% chance of a major anovulatory follicular wave arising before the ovulatory wave.
- There’s a 40% chance that a predeviation follicle will precede the ovulatory wave.
Role of Hormones and Age-Related Effects on Follicles
- Prior to deviation, there is a small but significant increase in estradiol and Luteinizing Hormone (LH).
- Follicle-Stimulating Hormone (FSH) and insulin-like growth factor 1, along with its proteases, play critical roles in the follicle deviation process.
- Age impacts the health and characteristics of follicles and oocytes in both mares and women.
Observations Pertaining to Ovulation
- There is an approximate 37-hour interval between the administration of Human Chorionic Gonadotropin (hCG) and ovulation in both mares and women.
- Both species exhibit similar gray-scale and color-Doppler ultrasound changes in the preovulatory follicle.
In conclusion, due to these similarities, the researchers suggest that mares could potentially be the best non-primate model for studying follicular dynamics in women.
Cite This Article
APA
Ginther OJ.
(2011).
The mare: a 1000-pound guinea pig for study of the ovulatory follicular wave in women.
Theriogenology, 77(5), 818-828.
https://doi.org/10.1016/j.theriogenology.2011.09.025 Publication
Researcher Affiliations
- Eutheria Foundation, Cross Plains, Wisconsin, USA. ginther@vetmed.wisc.edu
MeSH Terms
- Aging / physiology
- Animals
- Estradiol / blood
- Estradiol / physiology
- Female
- Follicle Stimulating Hormone / blood
- Follicle Stimulating Hormone / physiology
- Horses / physiology
- Humans
- Insulin-Like Growth Factor I / physiology
- Luteinizing Hormone / blood
- Luteinizing Hormone / physiology
- Models, Animal
- Oocytes / physiology
- Ovarian Follicle / physiology
- Ovulation / physiology
Citations
This article has been cited 14 times.- Gebremedhn S, Gad A, Ishak GM, Menjivar NG, Gastal MO, Feugang JM, Prochazka R, Tesfaye D, Gastal EL. Dynamics of extracellular vesicle-coupled microRNAs in equine follicular fluid associated with follicle selection and ovulation. Mol Hum Reprod 2023 Apr 3;29(4).
- Lu H, Ma L, Zhang Y, Feng Y, Zhang J, Wang S. Current Animal Model Systems for Ovarian Aging Research. Aging Dis 2022 Jul 11;13(4):1183-1195.
- Hyde KA, Aguiar FLN, Alves BG, Alves KA, Gastal GDA, Gastal MO, Gastal EL. Preantral follicle population and distribution in the horse ovary. Reprod Fertil 2022 Apr 1;3(2):90-102.
- Benammar A, Derisoud E, Vialard F, Palmer E, Ayoubi JM, Poulain M, Chavatte-Palmer P. The Mare: A Pertinent Model for Human Assisted Reproductive Technologies?. Animals (Basel) 2021 Aug 4;11(8).
- Gautam D, Vats A, Pal P, Haldar A, De S. Characterization of Anti-Müllerian Hormone (AMH) Gene in Buffaloes and Goats. Front Vet Sci 2021;8:627094.
- Souza SS, Alves BG, Alves KA, Brandão FAS, Brito DCC, Gastal MO, Rodrigues APR, Figueireod JR, Teixeira DIA, Gastal EL. Heterotopic autotransplantation of ovarian tissue in a large animal model: Effects of cooling and VEGF. PLoS One 2020;15(11):e0241442.
- 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.
- Vaiarelli A, Cimadomo D, Trabucco E, Vallefuoco R, Buffo L, Dusi L, Fiorini F, Barnocchi N, Bulletti FM, Rienzi L, Ubaldi FM. Double Stimulation in the Same Ovarian Cycle (DuoStim) to Maximize the Number of Oocytes Retrieved From Poor Prognosis Patients: A Multicenter Experience and SWOT Analysis. Front Endocrinol (Lausanne) 2018;9:317.
- Salgado RM, Brom-de-Luna JG, Resende HL, Canesin HS, Hinrichs K. Lower blastocyst quality after conventional vs. Piezo ICSI in the horse reflects delayed sperm component remodeling and oocyte activation. J Assist Reprod Genet 2018 May;35(5):825-840.
- Franciosi F, Tessaro I, Dalbies-Tran R, Douet C, Reigner F, Deleuze S, Papillier P, Miclea I, Lodde V, Luciano AM, Goudet G. Analysis of Chromosome Segregation, Histone Acetylation, and Spindle Morphology in Horse Oocytes. J Vis Exp 2017 May 11;(123).
- Alves KA, Alves BG, Gastal GD, de Tarso SG, Gastal MO, Figueiredo JR, Gambarini ML, Gastal EL. The Mare Model to Study the Effects of Ovarian Dynamics on Preantral Follicle Features. PLoS One 2016;11(2):e0149693.
- Feugang JM, Gad A, Menjivar NG, Ishak GM, Gebremedhn S, Gastal MO, Dlamini NH, Prochazka R, Gastal EL, Tesfaye D. Seasonal influence on miRNA expression dynamics of extracellular vesicles in equine follicular fluid. J Anim Sci Biotechnol 2024 Oct 9;15(1):137.
- Cardona-García M, Jiménez-Escobar C, Ferrer MS, Maldonado-Estrada JG. Follicular Dynamics and Pregnancy Rates during Foal Heat in Colombian Paso Fino Mares Bred under Permanent Grazing. Animals (Basel) 2024 Feb 29;14(5).
- Bashir ST, Baerwald AR, Gastal MO, Pierson RA, Gastal EL. Dominant follicle growth patterns and associated endocrine dynamics in anovulatory and ovulatory waves in women. Reprod Fertil 2023 May 1;4(2).
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