Characterization of the equine blood-testis barrier during tubular development in normal and cryptorchid stallions.
Abstract: The formation of the blood-testis barrier (BTB) is defined as occurring with the first appearance of spermatocytes at around puberty and is vital for normal spermatogenesis. This barrier between two adjacent Sertoli cells (SCs) consists of a cell junctional protein complex, which includes tight junctions (TJs), adherens junctions, and gap junctions. In many mammalian species, BTB composition has already been investigated, whereas little is known about the equine BTB. In the present study, immunohistochemistry and qualitative Western Blot analysis were used to assess the expression and distribution patterns of the junctional proteins claudin-11 (TJ), zonula occludens-1 (TJ associated), N-cadherin (adherens junctions), and connexin 43 (gap junctions) in equine testes during tubular development and in testes of stallions exhibiting unilateral cryptorchidism. Therefore, testes of 21 warmblood stallions (aged 12 months-11 years) were obtained during routine surgical castration. In the normal adult equine testis, the junctional proteins are localized at the basolateral region of the seminiferous tubules forming a circumferential seal corresponding to the known BTB localization. N-cadherin is additionally expressed along the lateral SC surface. In immature seminiferous cords still lacking a lumen, a diffuse distribution pattern of the junctional proteins throughout the SC cytoplasm is visible. As lumen formation advances, the immunolocalization shifts progressively toward the basolateral SC membranes. Additionally, apoptotic germ cells were detected and quantified in prepubertal stallions using terminal deoxynucleotidyl transferase dUTP nick end labeling assay and correlated with junctional protein localization. In the retained testis of cryptorchid stallions, which exhibit an aberrant testicular morphology, a deviating expression of the junctional proteins is visible. The present data show for the first time that (1) the equine SC junctional complex contains claudin-11, zonula occludens-1, N-Cadherin, and connexin 43, as already described for men or mice, and that (2) different distribution patterns of these proteins exist during testicular development in the context of lumen formation (lumen scores: 1-7) and in retained testes of unilateral cryptorchid stallions.
Copyright © 2015 Elsevier Inc. All rights reserved.
Publication Date: 2015-05-15 PubMed ID: 26074069DOI: 10.1016/j.theriogenology.2015.05.009Google 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.
- Journal Article
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 focuses on investigating the composition and development of the blood-testis barrier (BTB) in horses. Using tools like immunohistochemistry and Western Blot analysis, the researchers explored the presence and distribution of different junctional proteins within an equine testis during its development. They also identified and quantified apoptotic germ cells in prepubertal stallions to understand their relation to testicular development in horses.
About the Research
- This research investigates the composition and localization of junctional proteins which form the blood-testis barrier (BTB) in the testes of horses, a topic not well-studied previously.
- The BTB is formed by junctional proteins between Sertoli cells. It consists of tight junctions, adherens junctions, and gap junctions, and it first appears at the onset of puberty, playing a significant role in normal spermatogenesis.
Methodology
- Using the immunohistochemistry technique and qualitative Western Blot analysis, the study investigated the expression and distribution of junctional proteins in the testes during development and in cases of unilateral cryptorchidism, a condition where one or both of the testes fail to descend.
- The testes of 21 warmblood stallions aged 12 months to 11 years were used for sampling during routine surgical castration. The junctional proteins localized at the basolateral region of the seminiferous tubules were identified, forming a circumferential seal matching known BTB locations. N-cadherin was found extending along the lateral Sertoli Cell (SC) surface.
Findings
- In immature seminiferous cords that lacked a lumen, a variety of junctional proteins were diffusely distributed throughout the SC’s cytoplasm, which then progressively shifted towards the basolateral SC membranes as lumen formation advanced.
- Apoptotic germ cells were identified and quantified in prepubertal stallions and their correlation to the localization of junctional proteins was investigated.
- In cryptorchid stallions, which have an abnormal testicular morphology, the researchers found that the distribution of junctional proteins deviated from the norm.
- The findings suggest that the junctional complexes in the equine Sertoli Cells consist of the proteins claudin-11, zonula occludens-1, N-Cadherin, and connexin 43 as earlier reported in men and mice.
- It was also discovered that different distribution patterns of these proteins exist during testicular development and in the retained testes of unilateral cryptorchid stallions, linked to the different stages of lumen formation.
Cite This Article
APA
Rode K, Sieme H, Richterich P, Brehm R.
(2015).
Characterization of the equine blood-testis barrier during tubular development in normal and cryptorchid stallions.
Theriogenology, 84(5), 763-772.
https://doi.org/10.1016/j.theriogenology.2015.05.009 Publication
Researcher Affiliations
- Department of Anatomy, University of Veterinary Medicine Hannover, Hannover, Germany.
- Unit for Reproductive Medicine, Clinic for Horses, University of Veterinary Medicine Hannover, Hannover, Germany.
- Tierärztliche Klinik für Pferde auf Boyenstein, Beckum, Germany.
- Department of Anatomy, University of Veterinary Medicine Hannover, Hannover, Germany. Electronic address: Ralph.Brehm@tiho-hannover.de.
MeSH Terms
- Animals
- Blood-Testis Barrier / growth & development
- Blood-Testis Barrier / metabolism
- Blotting, Western
- Cadherins / metabolism
- Claudins / metabolism
- Connexin 43 / metabolism
- Gene Expression Regulation, Developmental
- Horses / physiology
- Immunohistochemistry
- In Situ Nick-End Labeling
- Male
- Sexual Maturation
- Testis / growth & development
Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
