Immunohistochemical Expression of Markers of Immaturity in Sertoli and Seminal Cells in Canine Testicular Atrophy

Chronic asymptomatic orchitis in dogs alters Sertoli cell number and maturation status

Infertility due to non-obstructive azoospermia is a common diagnosis in infertile male dogs. Chronic asymptomatic orchitis (CAO) has been postulated as a significant cause of non-obstructive azoospermia in acquired male canine infertility. Despite severe microenvironmental changes, some resilient spermatogonial stem cells persist in CAO-affected testes. As Sertoli cells play an essential role in spermatogenesis and the testicular micromilieu, they represent a new target for CAO potential treatment and consequently deserve further investigation. To investigate Sertoli cell number and maturational status, different markers [Vimentin, anti-Müllerian hormone (AMH), and cytokeratin-18 (CK18)] were evaluated in healthy and CAO-affected testes at mRNA and protein levels. Sertoli cell number was reduced in CAO-affected dogs. Sertoli cells also partly returned to an immature status, as indicated by the expression of AMH and CK18 at mRNA and protein levels. The degree of spermatogenesis disruption matched with the degree of Sertoli cell alterations. The investigation of CAO in this study is limited by the number of samples and the lack of testicular volume measurements, but this does not diminish its importance in new findings. In conclusion, this study identifies alterations in Sertoli cell number and maturation status as a cause or consequence of CAO. The results indicate the need to restore Sertoli cell function as a potential therapeutic target for a successful restart of spermatogenesis.

Pumpkin seed oil lessens the colchicine-induced altered sex male hormone balance, testicular oxidative status, sperm abnormalities, and collagen deposition in male rats via Caspase3/Desmin/PCNA modulation

This study examined the efficiency of pumpkin seed oil (PSO) to rescue the colchicine (CHC)-induced adverse impacts on sperm characteristics, male sex hormones, testicular architecture, oxidative status, DNA content, collagen deposition, and immune expression of desmin and PCNA. Male Sprague Dawley rats were divided into four experimental groups (n = 10 each): control (distilled water), CHC (0.6 mg/kg b.wt), PSO (4 mL/kg b.wt), and CHC + PSO. After 60 days of dosing, CHC significantly reduced sperm motility (19%), sperm concentration (38%), estradiol (52%), testosterone (37%), luteinizing hormone (54%), and follicle-stimulating hormone (29%) compared to the control. Yet, the testicular tissues of CHC-administered rats exhibited elevated abnormal sperms (156%), malondialdehyde (354%), lactate dehydrogenase (73%), Caspase-3 (66%), and 8-hydroxyguanosine (65%) but lower reduced glutathione (74%), catalase (73%), and superoxide dismutase (78%) compared to the control group. Moreover, CHC induced testicular degeneration, distorted seminiferous tubules, apoptotic cells, exfoliated spermatogenic cells, reduced DNA content, decreased PCNA and desmin immune-expression, and increased collagen deposition. PSO effectively reversed the CHC-induced alterations in sperm quality and testicular function and architecture, likely through its antioxidant, antifibrotic, anti-apoptotic, and DNA-protective properties. These results suggest that PSO may be a beneficial intervention for long-term CHC users and may protect against CHC-induced male reproductive toxicity.

Diagnostic Approach to Equine Testicular Disorders

Management of breeding stallions is crucial to equine reproduction. The longevity of the breeding career is the ultimate objective, whether the stallion is used for natural cover or for semen collection and artificial insemination. Stud farm veterinarians should be aware of the techniques used to evaluate testicular function and the diagnostic approach to testicular disorders in cases of emergency. This paper presents the clinical methods used to evaluate testicular health, including palpation, ultrasonography, biopsy, and fine-needle aspiration. The discussion of testicular disorders is broken down into four categories: congenital disorders (cryptorchidism, monorchidism, and testicular hypoplasia), differential diagnosis of scrotal enlargement, differential diagnosis of causes of progressive testicular enlargement, and differential diagnosis of testicular asymmetry or reduction in size with an emphasis on testicular degeneration. The sudden increase in testicular size is often accompanied by severe clinical signs and is a major cause for referral of stallion for surgery. Testicular disorders are illustrated with clinical cases seen by the authors.

Half-life of serum anti-Müllerian hormone and changes after gonadectomy in adult female and male dogs with normal and abnormal gonads

Anti-Müllerian hormone (AMH) is a biomarker for the presence of gonadal tissue. Changes in serum AMH after gonadectomy are not well established, and its serum half-life is unknown in dogs. We measured serum AMH with a validated electro-chemiluminescent immunoassay in adult female (n = 12) and male (n = 7) dogs with normal gonads, as well as in dogs with gonadal pathology (ovarian remnant syndrome, ORS n = 3, testicular tumor [Leydig cell, Sertoli cell, seminoma] n = 3, unilateral abdominal cryptorchid n = 4) on the day of gonadectomy (D0), and on D3, D7, D14 (females and males), and D21, D28 (males only). Males had higher AMH concentrations than females independent of gonadal status (P < 0.001). Dogs with ORS had lower initial AMH (0.45 ± 0.43 ng/ml) than bitches with normal gonads (1.16 ± 0.44 ng/ml; P = 0.027). Cryptorchid dogs had higher initial concentrations (80.57 ± 52.81 ng/ml) than males with normal gonads (7.92 ± 2.45 ng/ml; P = 0.004), and those with testicular tumors (18.63 ± 5.04 ng/ml) were intermediate (P ≥ 0.250). AMH decreased over time (P ≤ 0.012) and was 0.01-0.04 ng/ml by D14 in females and 0.02-0.12 ng/ml by D28 in males. Serum half-life in the whole study population was 2.85 ± 0.51 days and did not differ between groups. In conclusion, serum AMH can differentiate between intact and gonadectomized status of adult dogs by 14 days after ovario(hyster)ectomy in females and by 28 days after surgical castration in males.

Study on the expression of testin in the testes of dogs

Introduction

Testin is a protein involved in cell mobility, adhesion and colony formation. In rats, testin presence has been reported in the testes, and its possible role in spermatogenesis has been suggested. Studies in humans also suggest a possible role of testin as a cancer suppressor protein. In the dog, which represents both an important pet species and a good animal model for studying biological and pathological testicular processes, the presence of testin has never been reported.

Material and Methods

In the present study, the expression of testin in foetal, prepubertal, adult and aged canine testes was investigated. Testes from 5 adult and 3 aged dogs, from 2 one-month-old puppies and from 2 foetuses miscarried at the end of pregnancy were immunohistochemically examined with a commercial antibody against testin.

Results

Testin was intensely expressed in Sertoli cells in every testis examined. Spermatids were also positive for testin in mature dogs and in the testicular areas of the aged ones which were not atrophic. Weak expression of testin was also detected in all testes examined.

Conclusion

The present study, the first demonstrating the presence of testin in canine testes, provides the basis for further dog-human comparative research and for studies on the role of this protein in canine physiology, reproduction and testicular pathologies.

Geographic Variation in Testicular Morphometrics, Androgen Receptor Expression and Anti-Müllerian Hormone Levels in the Intermediate Roundleaf Bats across Distinct Regions in Thailand

The hipposideros larvatus (intermediate roundleaf bat) is one of the insectivorous bats which has an agro-ecological role as a controller of the insect population. The reproductive patterns of H. larvatus are intricately linked to its ecological role and survival. An understanding of the testicular morphology can contribute to conservation for this species particularly in areas where its populations might be declining or under threat. However, these bats may also be associated with zoonotic diseases which can have significant public health implications. The aims of the study were to examine the morphological data as well as the expression of the androgen receptor (AR) and anti-Müllerian hormone (AMH) in the male reproductive organs of H. larvatus from different areas of Thailand and at different sampling periods. Their testes were processed for histological investigation and immunohistochemistry for AR and AMH. The results showed differences among the various sampling areas and different sampling periods, which suggested seasonal breeding characteristics. The higher testicular morphometric data were observed in H. larvatus from the Dong Phayayen (DY) and Chiang Dao (CD) areas during June, while the size of seminiferous tubules decreased thereafter. High AR immunostaining was noticed when the testicular morphometric data were higher in DY bats during June. On the other hand, low AR was observed in bats during August and September, which was concomitant with the decreases in seminiferous tubule size and germinal epithelial height. The results suggest a potential correlation between AR immunostaining and the active phase of testicular functions in H. larvatus during June which may imply the involvement of AR with the enhancement of testicular activity. Conversely, the low expression of AR may contribute to the upregulation of AMH in the testes and may indicate lower testicular activity in H. larvatus in Thailand.

Anti-Müllerian hormone levels in serum and testes of male dogs: relations with neuter status and bilateral abdominal cryptorchidism

Anti-Müllerian hormone (AMH) analysis has contributed to new information in the reproductive endocrinology of domestic animals, due to clinically available diagnostic tools. An accurate and rapid diagnostic method to distinguish between neutered and bilateral abdominal cryptorchid dogs is needed in veterinary practice. Therefore, this study uses an enzyme-linked immunosorbent assay to evaluate the clinical relevance of AMH analysis in peripheral blood as a diagnostic tool for dogs with suspected bilateral abdominal cryptorchidism. The possible alteration of the AMH localization in testicular tissue caused by this pathologic condition was also investigated using immunohistochemistry. Male dogs were divided into three groups of healthy intact (n = 14), healthy castrated (n = 14), and bilateral abdominal cryptorchid (n = 14) dogs. The results demonstrated a higher level of serum AMH in the cryptorchid group compared to the intact group (P < 0.01), while serum AMH levels of all castrated dogs were below the limit of detection (<0.05 ng/mL). Moreover, the percentage of positive AMH immunostaining of the intact group was less than that of the cryptorchid group (P < 0.01). A significantly positive correlation was found between serum AMH concentration and localization in testicular tissues (r = 0.93, P < 0.01). Our findings suggest that AMH levels in the peripheral blood could be used as an alternative and rapid screening method for detecting dogs with abdominal cryptorchidism.

Anti-Müllerian Hormone Concentrations for Determining Resumption of Sertoli Cell Function following Removal of a 4.7 mg Deslorelin Implant in Tomcats

Background: Deslorelin implant use in cats is a medical alternative to surgical sterilization, and due to its prolonged efficacy, its use has shown growing interest in the veterinary community. In the case of breeding facilities, its removal is often requested for the early restoration of testicular function. As anti-Müllerian hormones (AMH) in males is dependent of testosterone secretion, its assay may determine the restoration of testicular steroid secretion. An average of 3 weeks has been already described for tomcats' testicular function resumption after implant removal, but information about AMH concentrations in deslorelin-treated tomcats is lacking. Methods: Fourteen tomcats were treated for temporary suppression of fertility with a 4.7 mg deslorelin implant, which was surgically removed after 3, 6 or 9 months (n = 6, 4 and 4 tomcats, respectively). A general clinical and reproductive check with a gonadorelin stimulation test for testosterone determination was performed before deslorelin implant administration. After implant removal, tomcats' testicles were ultrasonographically checked for volume determination every 1-2 weeks with observation of the glans penis (presence or absence of spikes) and blood collection to assay both testosterone and AMH concentrations. Results: AMH concentrations increased significantly during the deslorelin treatment from 20.95 ± 4.97 ng/mL to 82.41 ± 14.59 ng/mL (p < 0.05). Following implant removal, AMH concentrations progressively decreased to pre-treatment levels, with a value of 28.42 ± 7.98 ng/mL on the third week post-removal where testosterone secretion was again detected. Conclusions: Even if a big variability of AMH concentrations exists between male individuals, resumption of tomcats' testicular function following a deslorelin treatment can be determined by AMH assay.

[Diagnostic utility of the anti-Mullerian hormone in companion animals]

The anti-Mullerian hormone is a glycoprotein secreted by Sertoli cells in males and granulosa cells in females. The initial identification of this hormone in canine and feline serum was achieved in 2011. Meanwhile, a variety of studies have demonstrated its clinical significance as a tool in the endocrine diagnosis. This review summarizes the current knowledge about anti-Mullerian hormone in small animal reproduction and describes future opportunities for its diagnostic usage.

Distribution of cytoskeletal proteins in the cat testis during the pre-pubertal and post-pubertal periods

Cytoskeletal proteins not only define the shape of cells, but also have critical roles in their proliferation, migration and motility, as well as in the establishment and maintenance of tissue organization and integrity. Furthermore, these proteins influence the physiological processes of the male reproductive system and are found in the structure of some cells. This study aimed to determine differences between the pre- and post-pubertal periods for the localization and distribution of actin, desmin, vimentin and cytokeratin-18 in the testes, epididymides and ductus deferentes of Persian and Turkish Angora and Van cats, using immunohistochemistry. The study material was grouped as belonging to the pre-pubertal and post-pubertal periods. The tissue samples of both groups were subjected to routine histological processing and embedded in paraffin. Serial sections cut from the paraffin-embedded tissue blocks were immunohistochemically stained with the indirect streptavidin-biotin complex method. Immunohistochemical findings demonstrated that there was no difference between the pre- and post-pubertal periods for the staining intensity and distribution of the proteins actin, vimentin, desmin and cytokeratin-18 in Persian and Turkish Angora and Van cats. On the other hand, differences were detected between the pre- and post-pubertal periods for the cellular expression and localization of these proteins in the testes, epididymides and ductus deferentes. Thus, the study results suggest that, based on the expression of actin, desmin, vimentin and cytokeratin-18 in the testes, epididymides and ductus deferentes during both periods, these molecular factors could have a contributory role in the development of the male reproductive system and the regulation of its physiological processes.

Abundance of estrogen receptors involved in non-canonical signaling in the dog testis

With estrogen regulation of the reproductive system, G-protein-coupled membrane estrogen receptor (GPER) and estrogen-related receptors (ERRs) are implicated. Non-canonical receptors can bind estrogens such as environmental and pharmacological chemicals. These compounds induce rapid non-genomic pathways or receptor interaction including autoactivation. Testicular tumors occur in dogs more frequently than in other domestic animals. Also, in recent decades there were increased occurrences of various tumor types in dogs. Using qRT-PCR, Western blot and immunohistochemistry procedures in the present study, there was determination of abundance pattern of GPER, ERRα, β and γ in dog tests when there were intratubular germ cell tumors. There was quantitation of estradiol, cyclic GMP and calcium ions (Ca2⁺). There were changes (P < 0.01; P < 0.001) in GPER, ERRα and β in both mRNA transcript and protein abundances including less (P < 0.001) co-abundance of ERRγ mRNA transcript and protein. Receptors were mainly located in Leydig cells with there being receptor delocalization to the cell cytoplasm or occasionally detections in the seminiferous tubule epithelia, especially of testicular tumor tissues. There were also greater estradiol (P < 0.05) and lesser cGMP and Ca2⁺ concentrations in testicular tumor tissues indicating there was a disrupted sex steroid milieu and tumor cell metastasis. Results from the present study provide further evidence that ERRγ has marked actions in testicular germ cell tumor initiation and development and in further structural-functional disruptions of dog testis. Concomitantly, abundance pattern of GPER and ERRs, relative to concentrations of cGMP and Ca2⁺, may be an additional indicator of intratubular germ cell tumors in dogs.

Immunohistochemical insights into a hidden pathology: Canine cryptorchidism

Cryptorchidism is a common disorder in the canine population with some aspects still unclear. Although the bilateral condition is known to lead to fertility problems and predisposition to testicular cancer, the neoplastic risk for scrotal testis in unilateral cryptorchid dog is controversial. Therefore, the therapeutic approach to the canine unilateral cryptorchid is arbitrary so far. This study aimed to investigate precancerous testicular lesions, such as immaturity and atrophy, and compare them in scrotal and undescended testes using an in-depth diagnostic analysis based on immunophenotypic patterns. With this purpose, 26 adult male dogs of different ages and breeds, affected by unilateral or bilateral cryptorchidism were enrolled. After surgical removal, testes were examined immunohistochemically to assess their positivity for specific markers of the canine foetal/neonatal period, that is vimentin (VIM), cytokeratin (CK), desmin (DES), inhibin-α (INH), and anti-Müllerian hormone (AMH) in Sertoli cells, and placental alkaline phosphatase (PLAP) in germ cells. Except for the ubiquitous VIM, all the markers were more expressed in neoplastic gonads compared to healthy ones (P < 0.05). Similarly, testes detected with Sertoli cell-only tubules as well as with Sertoli cells hyperplasia showed higher expression than gonads without such alterations for CK, DES, AMH and PLAP, and for CK and DES, respectively (P < 0.05). The same trend was observed in undescended respect to scrotal testes even though their positivity was significant only for DES, INH and AMH (P < 0.05). Immunohistochemical positivity found in scrotal testes of unilateral cryptorchid dogs, even in absence of detectable anatomical abnormalities, was suggestive of precancerous lesions. Despite the limited sample size, this study could help to clarify the predisposition to neoplastic development in normally descended testes. These markers expression in adult life could allow identifying the early stages of the testicular carcinogenesis process besides suggesting a precautionary bilateral surgical approach in unilateral cryptorchid dogs.

Anti-Müllerian hormone, testosterone, and insulin-like peptide 3 as biomarkers of Sertoli and Leydig cell function during deslorelin-induced testicular downregulation in the dog

The role of anti-Müllerian hormone (AMH) and insulin-like peptide 3 (INSL3) in male infertility is not fully understood. We used the downregulated testis as a model of gonadotropin-dependent infertility. Serum testosterone and AMH concentrations were studied in five adult male Beagles implanted (day 0) with 4.7 mg deslorelin (Suprelorin®, Virbac) (DES group). Testicular expression of LH receptor (LHR) and androgen receptor (AR), AMH, type 2 AMH receptor (AMHR2), INSL3 and its receptor (RXFP2) was evaluated 112 days (16 weeks) after deslorelin treatment by qPCR and immunohistochemistry, and compared to untreated adult (CON, n = 6) and prepubertal (PRE, n = 8) dogs. Serum testosterone concentration decreased significantly by the onset of aspermia on study day 14 (four dogs) or day 21 (one dog), and was baseline on day 105 (week 15). In contrast, serum AMH started to increase only after the onset of aspermia and reached the maximum detectable concentration of the assay by day 49-105 in individual dogs. Testicular LHR gene expression in DES was lower than in CON and PRE (P < 0.0001), while AR gene expression in DES was similar to CON and significantly higher than PRE (P < 0.0001). Testicular AMH expression in DES was intermediate compared to the lowest mRNA levels found in CON and the highest in PRE (P ≤ 0.006). AMHR2 gene expression was similar between groups. AMH protein was detected in Sertoli cells only, while AMHR2 immunoreactivity was principally detected in Leydig cells which appeared to be increased in DES. INSL3 and RXFP2 gene expression was significantly downregulated in the DES testis along with noticeably weak Leydig cell immunosignals compared to CON. In conclusion, deslorelin treatment caused testicular LH insensitivity without affecting androgen sensitivity, and de-differentiation of Sertoli and Leydig cells. In DES, upregulation of the AMH-AMHR2 feed-back loop and downregulation of the INSL3-RXFP2 feed-forward loop are paracrine-autocrine mechanisms that may additionally regulate testosterone production independent of gonadotropins. Our results support AMH and INSL3 as unique biomarkers and paracrine-autocrine regulators of testis function involved in the intimate interplay between Sertoli and Leydig cells.

Common markers of testicular Sertoli cells

INTRODUCTION

Sertoli cells play central roles in the development of testis formation in fetuses and the initiation and maintenance of spermatogenesis in puberty and adulthood, and disorders of Sertoli cell proliferation and/or functional maturation can cause male reproductive disorders at various life stages. It's well documented that various genes are either overexpressed or absent in Sertoli cells during the conversion of an immature, proliferating Sertoli cell to a mature, non-proliferating Sertoli cell, which are considered as Sertoli cell stage-specific markers. Thus, it is paramount to choose an appropriate Sertoli cell marker that will be used not only to identify the developmental, proliferative, and maturation of Sertoli cell status in the testis during the fetal period, prepuberty, puberty, or in the adult, but also to diagnose the mechanisms underlying spermatogenic dysfunction.

AREAS COVERED

In this review, we principally enumerated 5 categories of testicular Sertoli cell markers - including immature Sertoli cell markers, mature Sertoli cell markers, immature/mature Sertoli cell markers, Sertoli cell functional markers, and others.

EXPERT OPINION

By delineating the characteristics and applications of more than 20 Sertoli cell markers, this review provided novel Sertoli cell markers for the more accurate diagnosis and mechanistic evaluation of male reproductive disorders.

Proteomic and phosphoproteomic profiles of Sertoli cells in buffalo

Sertoli cells provide nutrients and support for germ cell differentiation and maintain a stable microenvironment for spermatogenesis. Comprehensive identification of Sertoli cellular proteins is important in understanding spermatogenesis. In this study, we performed an integrative analysis of the proteome and phosphoproteome to explore the role of Sertoli cells in spermatogenesis. A total of 2912 and 753 proteins were identified from the proteome and phosphoproteome in Sertoli cells, respectively; 438 proteins were common to the proteome and phosphoproteome. Data are available via ProteomeXchange with identifier PXD024984. In the proteome, ACTG1, ACTB, ACTA2, MYH9 were the most abundant proteins. Gene Ontology (GO) analysis indicated that most of the proteins were involved in the processes of localization, biosynthesis, gene expression, and transport. In addition, some of the proteins related to Sertoli cell functions were also enriched. In the phosphoproteome, most of the proteins were involved in gene expression and the RNA metabolic process; the pathways mainly involved the spliceosome, mitogen-activated protein kinase signaling pathway, focal adhesion, and tight junctions. The pleckstrin homology-like domain is the most highly enriched protein domain in phosphoproteins. Cyclin-dependent kinases and protein kinases C were found to be highly active kinases in the kinase-substrate network analysis. Ten proteins most closely related to network stability were found in the analysis of the network interactions of proteins identified jointly in the phosphoproteome and proteome. Through immunohistochemistry and immunofluorescence verification of vimentin, it was found that there were localization differences between phosphorylated and non-phosphorylated vimentin in testicular tissue. This study is the first in-depth proteomic and phosphoproteomic analysis of buffalo testicular Sertoli cells. The results provide insight into the role of Sertoli cells in spermatogenesis and provide clues for further study of male reproduction.

Senescence and adiponectin signaling - Studies in canine testis

BACKGROUND

The meaning of senescence for tissue physiological and pathological conditions is poorly known. Based on initial reports especially proteins and mechanisms that regulate this process are necessary to be determinate.

METHODS

The main aim of the study was to investigate the presence of senescent cells in canine testicular tissue (mixed breed testes; n = 60) in relation to adiponectin signaling. In detail, new information on the senescence cell number, as well as senescence and adiponectin signaling mechanisms in cryptorchid and germ cell tumor testes were provided with the use of immunohistochemical and colorimetric analyses.

RESULTS

Comparison of immunohistochemical results, in cryptorchid and tumor testes revealed increased number of senescent cells (p16 and γH2AX markers). Increased expression of adiponectin and adiponectin receptor 1, as well as extracellular signal-activated kinase (ERK1/2) in pathological testes were detected. In addition, decreased cholesterol and increased testosterone levels in tumor testis were found.

CONCLUSION

The present study is the first to demonstrate the presence as well as the differences that exist in senecent cell number in mixed breed dog testes with cryptorchidism and germ cell tumor. Altered expression of adiponectin signaling and ERK1/2 signaling pathways together with altered cholesterol and testosterone levels reflect important senescence role in disturbed functions of canine testis. Moreover, the application of studied here senescence regulating molecules for detection and prevention against pathologies of the male gonad should be furtherly considered.

Anti-Müllerian hormone in dogs and cats reproduction

The anti-Müllerian hormone (AMH) is a glycoprotein secreted by Sertoli cells in males and granulosa cells in females. It has first been determined in blood serum of dogs and cats by Place et al. in 2011 with the use of a human-based ELISA test. Meanwhile, different immunoassays have been validated for AMH determination in animals and a variety of studies have demonstrated the clinical significance of AMH. This review summarizes the current knowledge about AMH in dogs and cats and describes future opportunities for its diagnostic use.

Evaluation of Canine Sperm and Management of Semen Disorders

Semen evaluation of the male dog is a critical step in any canine infertility work-up. Assessment of total sperm count, sperm viability, and sperm morphology are the mainstay of breeding soundness evaluation. Adjunct tests, such as ultrasonography and serum hormone levels, can aid in diagnosis. Pharmacologic treatments, dietary supplements, and management practices may help improve breeding success in subfertile dogs. This article discusses a clinically practical approach to assessing sperm abnormalities and fertility in male dogs.

Effect of age and castration on serum anti-Müllerian hormone concentration in male alpacas

The synthesis of anti-Müllerian Hormone (AMH) by the Sertoli cells in males is crucial for sexual differentiation. There are no studies on AMH in Camelids. The objectives of this research were to 1) compare AMH serum concentrations in prepubertal and adult male alpacas and 2) determine the effect of castration on these concentrations in adult males to provide a validation of a commercial AMH test in alpacas. Serum samples were obtained from 15 prepubertal animals (5 for each age groups of 6, 7 and 8 months) and from 5 adult males (age 5-9 years), pre- and 24 h post-castration. AMH was determined with a quantitative ELISA according to the manufacture's instructions. There was not significant difference (P < 0.05) in AMH level (pg/ml) between pre-pubertal (549.9 ± 120.8, 789.4 ± 172.3, 597.5 ± 177.3 for ages 4, 7, and 8 months, respectively) and adult alpacas (938.7 ± 175.9). In adult males, AMH concentration decreased significantly following castration (P < 0.05) (938.7 ± 383.5 pg/ml) pre-castration, and 222.1 ± 116.5 pg/ml) after castration). There was a positive correlation between testosterone levels and AMH. In conclusion, the quantitative assay used is a reliable test to determine AMH in alpacas. The AMH level in prepubertal and adult alpacas appear to not differ, contrarily from other mammals, this requires further investigation. The decrease in serum AMH concentrations after castration suggests that measurement of this hormone can be used to diagnose bilateral cryptorchid or hemicastrated unilateral cryptorchid animals in this species.

Immunophenotyping of Rabbit Testicular Germ and Sertoli Cells Across Maturational Stages

During testicular maturation, both Sertoli cells (SCs) and germ cells (GCs) switch from an immature to a mature immunophenotype. The reexpression of markers of immaturity in adults has been reported in cancer and in other testicular pathologies, in men as well as in animal species. Naturally affected with testicular cancer, rabbits have long been used in human reproductive research, but reports on the expression of testicular cell markers in this species are few and data about the immunophenotype of normal postnatal SCs and GCs are lacking. The aim of this study was to investigate the immunophenotype of SCs and GCs in the rabbit, from neonatal to adult age, using the antibodies anti-Müllerian hormone (AMH), vimentin (VIM), CKAE1/AE3 (cytokeratins [CKs]), desmin (DES), inhibin alpha (INH-α), placental alkaline phosphatase (PLAP), and periodic acid-Schiff (PAS) staining. In SCs, VIM was constantly expressed, and AMH and CKs expression was limited to neonatal and prepubertal age, whereas DES, INH-α, PLAP, and PAS were constantly negative. GCs were negatively stained for PLAP, PAS, and for the other markers. Results revealed analogies with human testicular immunophenotype, suggesting that rabbits could represent a potential experimental model for the study of human testicular pathology.

Vitrified canine testicular cells allow the formation of spermatogonial stem cells and seminiferous tubules following their xenotransplantation into nude mice

Belgian Malinois (BM), one of the excellent military dog breeds in South Korea, is usually castrated before sexual maturation. Therefore, the transfer of their genetic features to the next generation is difficult. To overcome this, testicular cells from 4-month-old BMs were frozen. Testicular cells were thawed after 3 months and cultured in StemPro-34 medium. Spermatogonial stem cell (SSC) characteristics were determined by the transplantation of the cultured germ cell-derived colonies (GDCs) into empty testes, containing only several endogenous SSCs and Sertoli cells, of immunodeficient mice, 4 weeks after busulfan treatment. Following the implantation, the transplanted cells localized in the basement membrane of the seminiferous tubules, and ultimately colonized the recipient testes. Xenotransplantation of GDCs together with testicular somatic cells conjugated with extracellular matrix (ECM), led to the formation of de novo seminiferous tubules. These seminiferous tubules were mostly composed of Sertoli cells. Some germ cells were localized in the basement membrane of seminiferous tubules. This study revealed that BM-derived SSCs, obtained from the castrated testes, might be a valuable tool for the transfer of BM genetic features to the next generation.

Anti-Müllerian hormone: a potentially useful biomarker for the diagnosis of canine Sertoli cell tumours

Background

Testicular tumours are common in dogs and in many cases do not give rise to clinical signs. In other cases, signs of feminization, hyperpigmentation or alopecia may be observed, most commonly associated with Sertoli cell tumours (SCT). Although these signs are often associated with elevated concentrations of oestradiol, analysis of oestradiol may give inconclusive results due to large variations among individuals. Other biomarkers are therefore needed. Anti-Müllerian hormone (AMH) is expressed by the Sertoli cell. In humans, AMH has been shown to be a specific marker of Sertoli cell origin in gonadal tumours. Using immunohistochemistry, AMH has been shown to be a useful marker of immature and neoplastic Sertoli cells in dogs. The aim of the present study was to evaluate the clinical relevance of AMH analysis in peripheral blood in the diagnostic workup of dogs with suspected testicular tumours.

Results

Blood was collected from 20 dogs with a palpable testicular mass and from 27 healthy controls. Serum was analysed for oestradiol-17β using a RIA and for AMH using an ELISA. The Mann–Whitney U test was used to compare hormone concentrations between different groups.

All control dogs had AMH concentrations ≤ 10 ng/mL, except one outlier that had a concentration of 43 ng/mL. Six dogs with SCT or mixed tumours containing SCT had AMH concentrations higher than 22 ng/mL, significantly higher than AMH concentrations in control dogs (P = 0.0004). Concentrations between 10 and 22 ng/mL were found in about half of the dogs with non-neoplastic testicular pathologies or with testicular tumours other than SCTs. Age did not significantly affect concentrations of AMH in the control dogs.

Conclusion

AMH was shown to be a promising biomarker for the diagnosis of Sertoli cell tumours in dogs.