Androgens and Notch signaling cooperate in seminiferous epithelium to regulate genes related to germ cell development and apoptosis.

It was reported previously that in adult males disruption of both androgen and Notch signaling impairs spermatid development and germ cell survival in rodent seminiferous epithelium. To explain the molecular mechanisms of these effects, we focused on the interaction between Notch signaling and androgen receptor (AR) in Sertoli cells and investigate its role in the control of proteins involved in apical ectoplasmic specializations, actin remodeling during spermiogenesis, and induction of germ cell apoptosis. First, it was revealed that in rat testicular explants ex vivo both testosterone and Notch signaling modulate AR expression and cooperate in the regulation of spermiogenesis-related genes (Nectin2, Afdn, Arp2, Eps8) and apoptosis-related genes (Fasl, Fas, Bax, Bcl2). Further, altered expression of these genes was found following exposure of Sertoli cells (TM4 cell line) and germ cells (GC-2 cell line) to ligands for Notch receptors (Delta-like1, Delta-like4, and Jagged1) and/or Notch pathway inhibition. Finally, direct interactions of Notch effector, Hairy/enhancer-of-split related with YRPW motif protein 1, and the promoter of Ar gene or AR protein were revealed in TM4 Sertoli cells. In conclusion, Notch pathway activity in Sertoli and germ cells regulates genes related to germ cell development and apoptosis acting both directly and indirectly by influencing androgen signaling in Sertoli cells.

Immunolocalization of apelin receptor (APJ) in mouse seminiferous epithelium.

The apelin receptor (APJ) belongs to the member of the G protein-coupled receptor family, and expression of APJ has been reported in the different cell types of testis. The seminiferous tubules in the testis can be identified as different stages (I-XII). It has been also suggested that different factors could be expressed in stage and cell-specific manner in the seminiferous tubules. Recently, we also shown that expression of APJ is developmentally regulated in the testis from PND1 to PND42. Therefore, we analyzed the expression of APJ in the testis of adult mice by immunohistochemistry. Immunohistochemistry showed that the APJ was highly specific for the round and elongated spermatids with stage-dependent changes. The seminiferous tubules at stages I-VII showed APJ immunostaining in the spermatid steps 1-8, not steps of 13-16. The seminiferous tubules at stages IX-XII showed APJ immunostaining in the spermatid steps 9-12. These results suggested the possible role of APJ in the spermiogenesis process. The intratesticular administration of APJ antagonist, ML221 showed a few round spermatids in the seminiferous tubules and some of the tubules with complete absence of round spermatid. Overall, we present evidence that APJ expression in spermatid is dependent on the stages of the seminiferous epithelium cycle and APJ could be involved in the differentiation of round spermatid to elongated spermatid.

Effect of Induced Pulmonary Arterial Hypertension on Testicular Parameters of Wistar Rats Subjected to Resistance Exercise Training.

Pulmonary arterial hypertension (PAH) is characterized by elevated arterial pressure and vascular resistance. PAH may cause alterations in the microcirculation of several organs, including the kidney, liver, brain, and testes. However, it remains unclear whether monocrotaline-induced PAH exerts detrimental effects on animal testes. Thus, we analyzed the impact of PAH on testicular morphology and function. Additionally, we investigated the effect of resistance exercise training (RT) on testicular parameters in PAH rats. Eight healthy Wistar rats and eight PAH rats were subjected to RT training for 30 days; the other PAH and healthy rats (n = 8/group) did not exercise. PAH rats had lower reproductive organ weight, serum testosterone levels, testicular glucose, and nitric oxide (NO) levels, Leydig cell parameters, tubular morphometry, germ cell counts, and daily sperm production than healthy animals did. The practice of RT attenuated the negative impact of PAH on the relative weights of the testes and epididymides, Leydig cell number, nuclear volume, testicular NO levels, and seminiferous epithelium architecture. Moreover, RT positively influenced testosterone levels in PAH animals. We conclude that PAH exerts deleterious effects on testicular histology and function. However, RT can be beneficial to the PAH-affected testicular parameters.

Cryptorchidism: The dog as a study model.

Cryptorchidism (CO) or undescended testicle is an abnormality of male gonadal development that can generate long-term repercussions in men, such as infertility and germ cell neoplasia in situ (GCNIS). The origin of these alterations in humans is not completely clear, due to the absence of an animal model with similar testicular development as in humans with CO. This work intends to describe the testicular histological development of dogs with congenital CO, and determine whether the species could adequately serve as a study model for this pathology in humans. The study was carried out with 36 dogs, equally distributed in two groups: healthy control (CTRL) and CO groups. The contralateral testis to the undescended one in CO group of the animals was considered and analyzed. Each group was subdivided in three stages of development: (1) peripubertal stage (6-8 months), (2) young adult (9-48 months) and (3) senile (49-130 months). Histological development, the presence of cells with gonocyte morphology, cell proliferation, testicular lipoperoxidation and hormonal concentrations of testosterone, estradiol, FSH and LH were evaluated and described. In the cryptorchid testes, the first histological alterations appeared from the first stage of development and were maintained until the senile stage. A pronounced testicular lipoperoxidation occurred only in the second stage of development. The histological alterations due to CO were markedly evident in the young adult stage. Testosterone concentrations witnessed a decrease starting from in the second stage and kept on until the last stage. The contralateral testes of the CO animals showed alterations that positioned them between the control and CO testes. Testicular development of dogs with CO is similar to that of humans. The results of the study suggest that this species could serve as a suitable model for the study of CO in humans.

Cellular Modifications in Spermatogenesis during Seasonal Testicular Regression: An Update Review in Mammals.

Testicular regression occurs during the non-breeding season in many mammals. This affects spermatogenesis, resulting in decreased or arrested activity. Both lead to a decrease or cessation in sperm production. In recent years, the cellular mechanisms that lead to infertility in males in non-reproductive periods have been studied in very different species of mammals. At the start of the present century, the main mechanism involved was considered as an increase in the apoptotic activity of germ cells during the regression period. The loss of spermatogonia and spermatocytes causes not only a decrease in spermatogenesis, but an arrest of the seminiferous epithelium activity at the end of regression. Recently, in some mammal species, it was found that apoptosis is the usual mechanism involved in epithelium activity arrest, although it is firstly atrophied by massive desquamation of the germ cells that are released from their binding with the Sertoli cells, and which are shed into the lumen of the seminiferous tubule. In other species, it has been shown that not only germ cell apoptosis, but also Sertoli cell apoptosis, including decreased proliferative activity, spermatophagy or autophagy, are involved in testicular regression. Furthermore, the most recent studies indicate that there are multiple patterns of seminiferous epithelium regression in seasonally breeding animals, which may not only be used by different species, but also by the same ones to reproduce in the best conditions, ensuring their survival. In conclusion, at this time, it is not possible to consider the existence of a paradigmatic cellular mechanism in the involution of the seminiferous epithelium applicable to all male mammals with seasonal reproduction, rather the existence of several mechanisms which participate to a greater or lesser extent in each of the species that have been studied to date.

Effects of bisphenol A and estradiol in adult rat testis after prepubertal and pubertal exposure.

Over the past few decades, male fertility has been decreasing worldwide. Many studies attribute this outcome to endocrine disruptors exposure such as bisphenol A (BPA), which is a chemical compound used in plastics synthesis and exhibiting estrogenic activity. In order to assess how the window of exposure modulates the effects of BPA on the testis, prepubertal (15 dpp to 30 dpp) and pubertal (60 dpp to 75 dpp) male Sprague-Dawley rats were exposed to BPA (50 µg/kg bw/day), 17-ß-estradiol (E2) (20 µg/kg bw/day) as a positive control, or to a combination of these compounds. For both periods of exposure, the rats were sacrificed and their testes were collected at 75 dpp. The histological analysis and the quantification of the gene expression of testis cell markers by RT-qPCR confirmed the complete spermatogenesis in all groups for both periods of exposure. However, our results suggest a deleterious effect of BPA on the blood-testis barrier in adults after pubertal exposure as BPA and BPA+E2 treatments induced a decrease in caveolin-1 and connexin-43 gene expression; which are proteins of the junctional complexes. As none of these effects were found after a prepubertal exposure, these results suggested the reversibility of BPA's effects. Caution must be taken when transposing this finding to humans and further studies are needed in this regard. However, from a regulatory perspective, this study emphasizes the importance of taking into account different periods of exposure, as they present different sensitivities to BPA exposure.

Duck Tembusu virus infection causes testicular atrophy.

In recent years, Duck Tembusu virus (DTMUV) is becoming an important emerging and re-emerging pathogen that severely harms the poultry industry in China. The DTMUV disease was principally identified by a sharp decline in egg production, whereas few studies were focused on the virus-reproductive system interaction, especially male reproductive system. Herein, the present study was aimed at investigating the in vivo morphological changes in testis from DTMUV-infected adult Shaoxing ducks. After DTMUV infection, the gross observation indicated that the testis of DTMUV-infected ducks was significantly atrophied at 2 days post-infection (dpi), 4 dpi, and 8 dpi. At microscopic and ultrastructural level, morphological analysis revealed that DTMUV could lead to cytoplasmic vacuolation and exfoliation in seminiferous epithelium, decrease in the diameter of seminiferous tubule (ST), and even induce interstitial inflammation in duck testis. Ulteriorly, the spermatogenic cells, especially spermatocytes, are identified as the target cells of DTMUV infection in the testis of ducks through immunohistochemistry (IHC). And more notably, single virus particles and clustered virus particles were observed in the spermatogenic cells from infected ducks. In summary, our results comprehensively illustrated the effects of DTMUV infection on the testis, the morphological changes underlying testicular atrophy and identified the target cells of DTMUV infection in the testis of ducks.

Retinoic Acid Receptor Alpha Is Essential in Postnatal Sertoli Cells but Not in Germ Cells.

Retinoic acid signaling is indispensable for the completion of spermatogenesis. It is known that loss of retinoic acid nuclear receptor alpha (RARA) induces male sterility due to seminiferous epithelium degeneration. Initial genetic studies established that RARA acts in Sertoli cells, but a recent paper proposed that RARA is also instrumental in germ cells. In the present study, we have re-assessed the function of RARA in germ cells by genetically ablating the Rara gene in spermatogonia and their progenies using a cell-specific conditional mutagenesis approach. We show that loss of Rara in postnatal male germ cells does not alter the histology of the seminiferous epithelium. Furthermore, RARA-deficient germ cells differentiate normally and give rise to normal, living pups. This establishes that RARA plays no crucial role in germ cells. We also tested whether RARA is required in Sertoli cells during the fetal period or after birth. For this purpose, we deleted the Rara gene in Sertoli cells at postnatal day 15 (PN15), i.e., after the onset of the first spermatogenic wave. To do so, we used temporally controlled cell-specific mutagenesis. By comparing the testis phenotypes generated when Rara is lost either at PN15 or at embryonic day 13, we show that RARA exerts all of its functions in Sertoli cells not at the fetal stage but from puberty.

Spermatogenesis in a vulnerable South American cervid, dwarf red brocket (Mazama rufina).

The brocket deer (Genus Mazama) is a highly diverse cervid group distributed from Mexico to Argentina, with a downward population trend. However, literature on the basic reproductive biology of the genus is scarce. This work aimed to study biometric, histological and stereological aspects of the testes of Dwarf Red Brocket (Mazama rufina). Testes from free-ranging adult brockets (n = 3) were retrieved from necropsies. Testes were histologically processed. From histological images, several stereological parameters were estimated, and seminiferous epithelium cycle morphology was described. Testes volumes were between 8.2 and 18.4 ml and weights from 8.3 to 19.4 g. Gonadosomatic index (% paired-testes weight to body weight) went from 0.17 to 0.64. The tubular cross-sectional diameter was 179.8 ± 2.8 µm. Estimated volume densities for parenchyma and interstitium were 78.8% and 21.2% respectively. There were (in millions/ml) 96.0 ± 13.1 germ cells and 37.7 ± 6.0 somatic cells. Specific cell densities were (all expressed in millions/ml) as follows: spermatogonia 13.1 ± 4.2; primary spermatocytes 43.1 ± 5.0; round spermatids 36.8 ± 8.0 (lower density near the caudal pole, p < 0.01); sustentacular (Sertoli) cells 16.8 ± 4.1 and interstitial endocrine (Leydig) cells 17.4 ± 3.4. Sertoli cell index (germ cells per Sertoli cell) was 6.72. Eight stages of the cycle were described, and frequencies estimated, resembling those of goats. M. rufina adult testis anatomy is similar to that of other cervids and domestic ruminants, with an apparently lower spermatogenic efficiency. This work is a first approximation to the physiology of the testis of M. rufina. Basic knowledge of the reproductive physiology of vulnerable species may allow biotechnological approaches for the restitution of animal populations.

The Effect of Inhibin Immunization in Seminiferous Epithelium of Yangzhou Goose Ganders: A Histological Study.

The current study investigated the effect of inhibin immunization on germ cell numbers (spermatogonia, spermatocytes, round, and elongated spermatids), seminiferous tubules (ST) diameter, Johnsen's score, epithelial height (µm), luminal tubular diameter (µm), and number of ST per field (ST/field) of Yangzhou goose ganders. Histological evaluation showed apoptosis and regression of testes after inhibin (INH) immunization, with a concomitantly marked reduction in the round and elongated spermatids in the experiment (INH) group compared to the control group. The diameter of seminiferous tubules (ST) and epithelial height (EH) were positively correlated at 181, 200, and 227 days of age. In comparison, luminal tubular diameter (LD) was negatively correlated on day 227 to ST diameter and epithelial height. On day 227, many seminiferous tubules per field (ST/field) were negatively correlated to ST diameter, EH, and LD. INH immunization elevated ST diameter, EH, and LD, while Johnsen's score and number of ST/field had reciprocal expression. In conclusion, the concomitant effect of INH immunization and seasonality in breeding regressed germ cells and damaged spermatogenesis in seminiferous epithelium Yangzhou ganders.

Two distinct Sertoli cell states are regulated via germ cell crosstalk†.

Sertoli cells are a critical component of the testis environment for their role in maintaining seminiferous tubule structure, establishing the blood-testis barrier, and nourishing maturing germ cells in a specialized niche. This study sought to uncover how Sertoli cells are regulated in the testis environment via germ cell crosstalk in the mouse. We found two major clusters of Sertoli cells as defined by their transcriptomes in Stages VII-VIII of the seminiferous epithelium and a cluster for all other stages. Additionally, we examined transcriptomes of germ cell-deficient testes and found that these existed in a state independent of either of the germ cell-sufficient clusters. Altogether, we highlight two main transcriptional states of Sertoli cells in an unperturbed testis environment, and a germ cell-deficient environment does not allow normal Sertoli cell transcriptome cycling and results in a state unique from either of those seen in Sertoli cells from a germ cell-sufficient environment.

Spermatogenesis in the Roborovski hamster (Phodopus roborovskii) and the Chinese hamster (Cricetulus griseus).

BACKGROUND: Spermatogenesis is an elaborately organized and tightly regulated differentiation process. The spermatogenesis duration is stable within a certain species but highly variable between species of the same family. OBJECTIVES: In this study, the spermatogenesis duration of the Roborovski hamster was measured for the first time, and the spermatogenesis duration of the Chinese hamster was re-assessed. MATERIALS AND METHODS: Stage classification and cycle length measurement were carried out by labeling the dividing cells with bromodeoxyuridine and an antibody-based chromogen as well as with the periodic acid-Schiff/hematoxylin stain. Analysis was conducted using reference calculation and linear regression. Morphological measurements completed our set of methods. RESULTS: The mean duration of one seminiferous epithelium cycle was 8.58 ± 0.34 days (mean ± SEM; Phodopus roborovskii) and 16.59 ± 0.47 days (Cricetulus griseus) based on the reference calculation. Slightly higher results were obtained using linear regression analysis: 9.72 ± 0.41 days for P. roborovskii and 17.64 ± 0.61 days for C. griseus. Additionally, a newly developed exemplary flowchart was proposed for the Roborovski hamster to facilitate spermatogenesis stage classification also in other species. The Chinese hamster presented an unexpectedly high paired epididymides weight of 1.701 ± 0.046 g (mean ± SEM) although having a body weight of only 40.5 ± 0.7 g. However, no significant correlation between the relative epididymis weight and spermatogenesis duration in mammals (Spearman rank correlation: r = -0.119, p = 0.607, n = 21) or rodents could be found (r = 0.045, p = 0.903, n = 11). CONCLUSION: Our data emphasize the stability of the spermatogenesis duration within species and its remarkable variability between species. Further research is needed to identify the principal mechanisms and selection drivers that are responsible for such stability within species and the variability between species.

Immunodistribution of RFamide-related peptide-3 (RFRP-3) during the seminiferous epithelium cycle in a desert rodent Psammomys obesus.

The Sand rat, Psammomys obesus, living northwest of the Algerian Sahara, presents a seasonal reproductive cycle. The purposes of this study were firstly to determine the stages of seminiferous epithelium cycle (SEC) by histological and morphometric analysis and secondly to investigate, for the first time, the testicular expression of RFamide-related peptide-3 (RFRP-3) during the SEC by immunohistochemistry. The results showed that the SEC consists of 14 stages according to the tubular morphology method. RFRP-3 was observed in both testicular compartments: the tubular and the interstitial. Leydig cells exhibited the highest RFRP-3 signal (30.73 % ± 4.80) compared to Sertoli cells (13-15 %). In the germline, RFRP-3 was detected during the late prophase I of meiosis in late pachytene, diplotene and metaphasic spermatocytes I. In addition, only round and triangular spermatids were positive during spermiogenesis. Referring to the SEC, it was found that the increased staining of RFRP-3 in spermatocytes I coincided with late pachytene of XI and XII stages (16.90 % ± 0.69 and 16.61 % ± 0.28, respectively). In spermatids, the labeling decreased in the triangular ones at stage IX (8.04 % ± 0.42). These results suggest the involvement of RFRP-3 in the control of SEC in P. obesus.

Effect of low-level laser therapy on seminiferous epithelium: a systematic review of in vivo studies.

Laser therapy has proved effective in the treatment of different tissue injuries but little is known about its effect on the testis. The aim of this review was to synthesize research on the in vivo effect of low-level laser therapy on the seminiferous epithelium. A search was performed in the PubMed/Medline, Scopus, Web of Science, and LILACS databases. The initial search retrieved 354 references, and five articles that met the eligibility criteria were selected. In general, the studies showed that laser therapy exerted a positive effect on the germ cell population; however, there was considerable variation in the laser parameters, as well as in the experimental models and methods of tissue analysis used. In conclusion, further studies determining the biostimulation parameters of laser therapy in the testis are necessary in order to provide a basis for the possible application of this technique to the restoration of the human seminiferous epithelium and consequent treatment of some male reproductive disorders.

Acrosomal marker SP-10 (gene name Acrv1) for staging of the cycle of seminiferous epithelium in the stallion.

The acrosome plays a critical role in sperm-oocyte interactions during fertilization. SP-10 is an acrosomal matrix protein, which is evolutionarily conserved among mammals. The SP-10 antibody has been shown to be useful for staging the seminiferous cycle in the mouse and human. A canonical acrosomal marker; however, has never been used for staging in the horse. The objectives of the present study were to investigate the presence of SP-10 within the horse acrosome using an anti-mouse SP-10 antibody, to classify spermatids based on the shape of the acrosome, and then to use that information to assign stages of the cycle of the seminiferous epithelium. Testes from mature stallions with history of normospermic ejaculates were used for immunohistochemistry. We found that the mouse SP-10 antibody stained the horse acrosome vividly in testis cross-sections, indicating evolutionary conservation. Previous methods based on morphology alone without the aid of an antibody marker showed 8 stages in the horse seminiferous epithelium. Morphological detail of the acrosome afforded by the SP-10 marker in this study identified 16 steps of spermatids. This, in turn, led to the identification of 12 distinct stages in the cycle of the seminiferous epithelium of the horse wherein stage I shows recently formed round spermatids and stage XII includes meiotic divisions; a classification that is consistent with other animal models. The SP-10 antibody marks the acrosome in a way that enables researchers in the field to identify stages of spermatogenesis in the horse easily. In conclusion, we demonstrated that immunolabeling for SP-10 can be an objective approach to stage the cycle of the seminiferous epithelium in normospermic stallions; future studies will determine if SP-10 could be used to assess testicular dysfunction.

Toxicological effects of bioactive peptide fractions obtained from Bothrops jararaca snake venom on the structure and function of mouse seminiferous epithelium.

BACKGROUND: Pathogenesis of Bothrops envenomations is complex and despite numerous studies on the effects of this snake venom on various biological systems, relatively little is known about such effects on the male reproductive system. In the present study, the toxicological outcomes of the low molecular weight fraction (LMWF) of B. jararaca snake venom - containing a range of bioactive peptides - were investigated on the dynamics and structure of the seminiferous epithelium and 15P-1 Sertoli cells viability. METHODS: LMWF (5 µg/dose per testis) venom was administered in male Swiss mice by intratesticular (i.t.) injection. Seven days after this procedure, the testes were collected for morphological and morphometric evaluation, distribution of claudin-1 in the seminiferous epithelium by immunohistochemical analyses of testes, and the nitric oxide (NO) levels were evaluated in the total extract of the testis protein. In addition, the toxicological effects of LMWF and crude venom (CV) were analyzed on the 15P-1 Sertoli cell culture. RESULTS: LMWF induced changes in the structure and function of the seminiferous epithelium without altering claudin-1 distribution. LMWF effects were characterized especially by lost cells in the adluminal compartment of epithelium (spermatocytes in pachytene, preleptotene spermatocytes, zygotene spermatocytes, and round spermatid) and different stages of the seminiferous epithelium cycle. LMWF also increased the NO levels in the total extract of the testis protein and was not cytotoxic in concentrations and time tested in the present study. However, CV showed cytotoxicity at 10 µg/mL from 6 to 48 h of treatment. CONCLUSIONS: The major finding of the present study was that the LMWF inhibited spermatozoa production; principally in the spermiogenesis stage without altering claudin-1 distribution in the basal compartment. Moreover, NO increased by LMWF induce open of complexes junctions and release the germ cells of the adluminal compartment to the seminiferous tubule.

Effect of GnRH agonist deslorelin implant on spermatogenesis and testosterone concentration in Guinea pigs (Cavia aperea porcellus).

Guinea pigs are social animals that are often kept in groups regardless of their gender. Due to reproduction control and male aggressiveness prevention, surgical castration is commonly required. In the present study, we evaluated the effect of GnRH agonist implant (4.7 mg deslorelinum) on the serum testosterone concentration (T) and spermatogenesis in male guinea pigs. Twenty-four animals were divided into two groups. All animals in the first group were neutered (Group 1), animals in the second group (Group 2) were administered the implant subcutaneously and then neutered in one-month intervals. A histological examination was performed when cross sections of seminiferous tubules were assessed. Subsequently, these tubules were divided based on the most developed germ cell observed: spermatogonia, spermatocytes, round spermatids, elongating spermatids and elongated spermatids. The anticipated decrease in testosterone concentration and cessation of spermatogenesis was not achieved. Thus, the results obtained proved the inefficacy of the deslorelin implant in male guinea pigs so the alternative methods of contraception remain the methods of choice.

Regulation of Gdnf expression by retinoic acid in Sertoli cells.

Glial cell line-derived neurotrophic factor (GDNF) and retinoic acid (RA) are two molecules crucial for the regulation of the spermatogonial compartment of the testis. During the cycle of the seminiferous epithelium, their relative concentration oscillates with lower GDNF levels in stages where RA levels are high. It has been recently shown that RA negatively regulates Gdnf expression but the mechanisms behind are so far unknown. Here, we show that RA directly downregulates Gdnf mRNA levels in primary murine Sertoli cells through binding of RARα to a novel DR5-RARE on Gdnf promoter. Pharmacological inhibition and chromatin immunoprecipitation-quantitative polymerase chain reaction analysis suggested that the underlying mechanism involved histone deacetylase activity and epigenetic repression of Gdnf promoter upon RA treatment.

Toxicological effects of bioactive peptide fractions obtained from Bothrops jararaca snake venom on the structure and function of mouse seminiferous epithelium

Pathogenesis of Bothrops envenomations is complex and despite numerous studies on the effects of this snake venom on various biological systems, relatively little is known about such effects on the male reproductive system. In the present study, the toxicological outcomes of the low molecular weight fraction (LMWF) of B. jararaca snake venom - containing a range of bioactive peptides - were investigated on the dynamics and structure of the seminiferous epithelium and 15P-1 Sertoli cells viability. Methods: LMWF (5 µg/dose per testis) venom was administered in male Swiss mice by intratesticular (i.t.) injection. Seven days after this procedure, the testes were collected for morphological and morphometric evaluation, distribution of claudin-1 in the seminiferous epithelium by immunohistochemical analyses of testes, and the nitric oxide (NO) levels were evaluated in the total extract of the testis protein. In addition, the toxicological effects of LMWF and crude venom (CV) were analyzed on the 15P-1 Sertoli cell culture. Results: LMWF induced changes in the structure and function of the seminiferous epithelium without altering claudin-1 distribution. LMWF effects were characterized especially by lost cells in the adluminal compartment of epithelium (spermatocytes in pachytene, preleptotene spermatocytes, zygotene spermatocytes, and round spermatid) and different stages of the seminiferous epithelium cycle. LMWF also increased the NO levels in the total extract of the testis protein and was not cytotoxic in concentrations and time tested in the present study. However, CV showed cytotoxicity at 10 μg/mL from 6 to 48 h of treatment. Conclusions: The major finding of the present study was that the LMWF inhibited spermatozoa production; principally in the spermiogenesis stage without altering claudin-1 distribution in the basal compartment. Moreover, NO increased by LMWF induce open of complexes junctions and release the germ cells of the adluminal compartment to the seminiferous tubule.(AU)

Spermatid differentiation, with particular reference to acrosomogenesis, in the passeridan bird, Carib grackle (Quiscalus lugubris).

Only a few studies on the development of the passerine spermatozoon are available, yet species variations in the conformation as well as structure of the generally helical acrosome have been reported. This study of spermiogenesis in the Carib grackle (Quiscalus lugubris) intended to provide a deeper understanding of the development of the sperm, and in particular to investigate the bi-partite nature and development of the acrosome as well as its relationship with the nucleus, in the absence of a perforatorium that is found in most non-passerine birds. The acrosomal vesicle already displays a bi-partite nature in the acrosomal granule within the Golgi complex, and the attachment of the dense granule (future acrosomal core) within the crest part (future acrosomal crest) establishes polarity as it approaches and attaches to the nucleus. Thereafter, they develop variably. The acrosomal crest leads the elongation and spiraling of the acrosome, and the core portion contributes significantly to the formation of the keel of the crest part. The rounded, core-bearing part of the base of the acrosome progressively indents and fits into the concavity, thus formed, at the anterior part of the nucleus. The possible homology of the acrosomal complex (including the perforatorium) and the nucleus between non-passerine and passerine birds was discussed. The centriolar complex comprises both the proximal and distal centrioles in all spermatids and spermatozoa. The mitochondria undergo a number of morphological changes, including size and electron-density, from the round spermatid through to the mature spermatid; changes that are probably influenced by their functional states in the different evolving phases of the spermatids.