Equine disorders of sexual development in 17 mares including XX, SRY-negative, XY, SRY-negative and XY, SRY-positive genotypes.
Abstract: We described the clinical, cytogenetic and molecular findings of 17 clinical equine cases presented for abnormal sexual development and infertility. Six horses with an enlarged clitoris had an XX, SRY-negative genotype, which displayed male-like behavior (adult individuals). Bilateral ovotestes were noted in 2 of those cases, while another case showed increased levels of circulating testosterone. Six horses with a female phenotype, including normal external genitalia, had an XY, SRY-negative genotype. These individuals had small gonads and an underdeveloped internal reproductive tract. Four horses with normal appearing external genitalia had an XY, SRY-positive genotype, 3 of them had hypoplastic testes and male-like behavior. In addition, one young filly with enlarged clitoris and hypoplastic testes had the same genotype but did not show male-like behavior due to her age. Three of these horses were related with 2 being siblings. These findings demonstrate the diversity of disorders of sexual development seen in the horse. Furthermore, they emphasize the need for further research to identify genes involved in abnormal sex determination and differentiation in the horse.
Copyright © 2010 S. Karger AG, Basel.
Publication Date: 2010-12-22 PubMed ID: 21196712DOI: 10.1159/000322811Google Scholar: Lookup
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Summary
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The research study assessed the variation in sexual development disorders in 17 mares, exploring correlations between their genetics and their physical characteristics. Discrepancies between typical physical development and genetic sex markers were found.
Summary of Research Methodology
- The research utilized both clinical observation and cytogenetic and molecular investigation.
- 17 mares with abnormal sexual development and fertility issues were studied.
- Physical abnormalities included enlarged clitorises, small gonads, underdeveloped reproductive tracts, and hypoplastic testes.
- Behavioural anomalies, particularly male-like behaviour in mares, were also noted.
Key Findings
- The horses’ genes didn’t always correspond to their physical sexual attributes. Conditions found included:
- XX, SRY-negative genotypes: These horses had enlarged clitorises and demonstrated male-like behaviour. Some had ovotestes and increased testosterone levels.
- XY, SRY-negative genotypes: These horses had female physicality, including normal external genitalia, but their internal reproductive organs were underdeveloped and their gonads were small.
- XY, SRY-positive genotypes: These horses displayed normal exterior physical traits, but three of them had undersized testes and showed male behaviour. A young mare in the same group didn’t express male behaviour due to her age.
Interpretation and Implications
- The results reveal a diversity of sexual development disorders among horses.
- Findings confirm the complex relationship between genetics, physical attributes, and behavior as they relate to sexual development and fertility in horses.
- The discovery of these genetic-sexual physicality mismatches in a relatively small sample of horses points to the possibility of more widespread genetic-sexuality disorders within the equine population.
- Given some familial relations between the horses in the study, genetic inheritability may be another factor contributing to disorders of sexual development.
- This research demonstrates a need for further studies to identify the specific genes linked to these developmental anomalies in horses.
Cite This Article
APA
Villagómez DA, Lear TL, Chenier T, Lee S, McGee RB, Cahill J, Foster RA, Reyes E, St John E, King WA.
(2010).
Equine disorders of sexual development in 17 mares including XX, SRY-negative, XY, SRY-negative and XY, SRY-positive genotypes.
Sex Dev, 5(1), 16-25.
https://doi.org/10.1159/000322811 Publication
Researcher Affiliations
- Department of Biomedical Sciences, University of Guelph, Guelph, Ontario, Canada. dvilla@cucba.udg.mx
MeSH Terms
- Animals
- Chromosome Banding
- Disorders of Sex Development / genetics
- Disorders of Sex Development / pathology
- Disorders of Sex Development / veterinary
- Female
- Gene Deletion
- Genes, sry
- Genitalia / abnormalities
- Horse Diseases / genetics
- Horse Diseases / pathology
- Horses / genetics
- In Situ Hybridization, Fluorescence
- Male
- Phenotype
- Sex Determination Processes / genetics
- Sex Differentiation / genetics
Citations
This article has been cited 9 times.- Demyda-Peyrás S, Laseca N, Anaya G, Kij-Mitka B, Molina A, Karlau A, Valera M. Prevalence of Sex-Related Chromosomal Abnormalities in a Large Cohort of Spanish Purebred Horses.. Animals (Basel) 2023 Feb 3;13(3).
- Bugno-Poniewierska M, Raudsepp T. Horse Clinical Cytogenetics: Recurrent Themes and Novel Findings.. Animals (Basel) 2021 Mar 16;11(3).
- Laseca N, Anaya G, Peña Z, Pirosanto Y, Molina A, Demyda Peyrás S. Impaired Reproductive Function in Equines: From Genetics to Genomics.. Animals (Basel) 2021 Feb 3;11(2).
- Peretti V, Satué K, Ciotola F, Cristarella S, De Majo M, Biondi V, D'Anza E, Albarella S, Quartuccio M. An Unusual Case of Testicular Disorder in Sex Development of Arabian Mare (64,XX SRY-Negative).. Animals (Basel) 2020 Oct 25;10(11).
- Albarella S, Lorenzi L, Rossi E, Prisco F, Riccardi MG, Restucci B, Ciotola F, Parma P. Analysis of XX SRY-Negative Sex Reversal Dogs.. Animals (Basel) 2020 Sep 16;10(9).
- Ghosh S, Davis BW, Rosengren M, Jevit MJ, Castaneda C, Arnold C, Jaxheimer J, Love CC, Varner DD, Lindgren G, Wade CM, Raudsepp T. Characterization of A Homozygous Deletion of Steroid Hormone Biosynthesis Genes in Horse Chromosome 29 as A Risk Factor for Disorders of Sex Development and Reproduction.. Genes (Basel) 2020 Feb 27;11(3).
- Villagomez DAF, Welsford EG, King WA, Revay T. Androgen Receptor Gene Variants in New Cases of Equine Androgen Insensitivity Syndrome.. Genes (Basel) 2020 Jan 10;11(1).
- Albarella S, D'Anza E, Galdiero G, Esposito L, De Biase D, Paciello O, Ciotola F, Peretti V. Cytogenetic Analyses in Ewes with Congenital Abnormalities of the Genital Apparatus.. Animals (Basel) 2019 Oct 10;9(10).
- Albarella S, Ciotola F, D'Anza E, Coletta A, Zicarelli L, Peretti V. Congenital Malformations in River Buffalo (Bubalus bubalis).. Animals (Basel) 2017 Feb 10;7(2).
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