Effects of age and gonadal steroids on the localization of antigen presenting cells in the epididymis of the male chicken, Gallus domesticus

The goal of this study was to localize antigen presenting cells (APC), which may play roles in defense against pathogens and fertility, and examine the effects of age and gonadal steroids on their population in the rooster epididymis. Healthy White Leghorn male birds (immature 60-day-old birds; matured 150-, 330-, and 550-day-old), and immature birds treated with testosterone propionate (TP) or estradiol benzoate (EB) for 3 or 6 days were used. Cryostat sections of the epididymis and ductus deference were immunostained for Ia to identify APC. RT-PCR was performed to confirm the expression of major histocompatibility complex class II (MHC class II) mRNA in the epididymis. Ia+ cells were localized in the surface epithelium and subepithelial layer of the ductules and occasionally in the luminal content of the epididymis and ductus deference. RT-PCR analysis confirmed expression of MHC class II mRNA in the epididymis, ductus deferens, testis, and spleen. The frequency of Ia+ cells in the subepithelial layer was significantly greater in the proximal efferent ductules than in the other two types of ductules in the epididymis of 550-day-old birds. Although there were no significant differences in the frequencies in the subepithelial layer of the proximal efferent ductules between 60- and 150-day-old birds, the frequencies were significantly greater in 330- and 550-day-old birds than in 60-day-old birds. The frequencies of Ia+ cells in the ductus deferences was increased in the 150-day-old birds compared with the 60-day-old birds, with a larger increase in 330- and 550-day-old birds. The Ia+ cell frequency was significantly increased by EB-injection, but not by TP-injection, on Days 3 and 6 of injection compared with Day 0. These results suggest that the population of APC in the epididymis increases with age after sexual maturation, and estrogen may be one of the factors involved in induction of Ia+ cells.     

Localization of Oestrogen Receptors in the Epididymis During Sexual Maturation of the Domestic Cat

Oestrogens are involved in regulation of spermatogenesis and sperm maturation and are essential for male fertility. To study the role of oestrogens on epididymal function in the domestic cat, we analyzed the localization patterns of oestrogen receptors (ERs) within the epididymis of juvenile, pubertal and adults using immunohistochemistry. Cat epididymal tissues obtained during routine castrations were fixed in chilled Bouin's solution and processed for immunohistochemistry with ER-specific antibodies. For a certain receptor type, ER localization was influenced by donor age. In the juvenile epididymis, ERα was localized in the nuclei of epithelial cells of efferent ducts and undifferentiated epithelium of the ductus epididymis. During puberty, ERα localization in the undifferentiated epithelium of the epididymis shifted from the nuclei to the cytoplasm and plasma membrane. Oestrogen receptor-α level was highest in the pubertal and adult epididymis, especially within the cytoplasm and in plasma membranes of caput epithelial cells. This finding was suggestive of a role in fluid reabsorption within the efferent ducts and the epididymis. In corpus and cauda regions, ERα was less abundant, suggesting a minor role for oestrogens in sperm storage areas. Interestingly, localization of ERβ was neither influenced by age nor location within the epididymis and was ubiquitous throughout. Results demonstrate that oestrogen actions within the epididymis may be predominantly mediated through ERα during sexual maturation in the domestic cat.     

Effects of ligation of the ductus deferens on the fowl epididymal region

The effects of ligation of the ductus deferens on the epididymis in the fowl were studied histochemically and immunohistochemically to reveal the mechanisms of sperm disposal. At one week post-ligation, the lumina of the rete testes (RT) and the efferent ductules (ED) were distended and filled with densely accumulated spermatozoa. Macrophages and foreign-body giant cells were aggregated in and around the accumulations. The epithelium regressed in the initial portion of the RT with the invasion of fibroblasts and heterophiles into the lumen. The other part of the epithelium was penetrated by many spermatozoa. Numerous lymphocytes and plasma cells infiltrated into the interstitium. At 4 weeks, larger number of spermatozoa agglutinated in the lumen, and large masses of foamy cells and proliferated connective tissue protruded into the lumen. At 8 weeks, large masses of foamy cells were noted. The connecting ductules or the epididymal duct showed no marked changes after ligation. The epithelium of the ED showed weaker or no acid phosphatase activity after ligation. Immunoglobulin G-containing cells increased in number in the interstitium. These results showed that ligation of the ductus deferens in the fowl causes granuloma in the RT and ED, and that epithelial cells, macrophages and granuloma are engaged in the removal of spermatozoa. The participation of antibody is suggested in the sperm disposal processes.     

Histochemical Detection of Glycoconjugates in the Canine Epididymis

A histochemical study using fluorescein isothiocyanate (FITC)-labelled lectins to identify glycoconjugates present in the efferent ductules and the three segments of the ductus epididymis (initial, middle and terminal segment) of dogs was carried out. The lectins used were: mannose-binding lectins (Con A, LCA and PSA), galactose-binding lectins (PNA, RCA), N -acetylgalactosamine-binding lectins (DBA, SBA, SJA and GSL I), N -acetylglucosamine-binding lectins (WGA and WGAs), fucose-binding lectins (UEA) and lectins which bind to complex carbohydrate configurations (PHA E and PHA L). The lectin-binding pattern in the canine epididymis presents similarities and differences to those observed in other mammalian species. The ductuli efferentes distinctly stained with most of the lectins used, whereas in the ductus epididymis a segment specific staining pattern was observed. Whereas principal cells of the ductus epididymis stained clearly with several FITC-labelled lectins (WGA, UEA and PHA-L), basal cells showed only a significant binding of Con A.     

Immunolocalization of some HOX proteins in immature and mature feline testes

Homeobox (HOX) proteins are known for their critical role in body shape formation and tissue differentiation of developing vertebrate embryos. Recent research has shown that HOX proteins have many physiological roles such as cell proliferation, cell cycle, apoptosis and cell differentiation in adults, as well as the development of the vertebrate nerve and reproductive system. This study was conducted to determine the possible physiological functions and expression intensities of HOXA10, HOXA11, HOXB6 and HOXC6 proteins in the male reproductive system (testes, epididymis and deferens ducts), which are important for the continuity of some specific cat breeds in different age ranges. In the study, a total of 18 testicular tissues were used, divided into two groups: less than 6 months (immature) and more than 1 year (mature). Tissue samples were then subjected to immunohistochemical staining with protein-specific antibodies examined in the study. In the findings obtained in the research; it was observed that HOXA10, HOXA11, HOXB6 and HOXC6 produced different intensities of immunolocalization in the epididymis and ductus deferens layers in the immature and mature testicular cells. In addition, it was found that HOXA10 immunoreaction was also seen in some vascular endothelial cells. As a result, it was concluded that the HOX proteins could contribute to the physiological functions of testes, epididymis and ductus deferens and affect male fertility.     

Ultrastructural study of the luminal surface of the ducts of the epididymis of gallinaceous birds

The various ducts of the epididymides of four gallinaceous birds, the turkey (Meleagris gallopavo), domestic fowl (Gallus gallus), guinea-fowl (Numida meleagris) and Japanese quail (Coturnix coturnix japonica) were studied at the scanning and transmission electron microscopy levels. The tissues were fixed either by immersion or vascular perfusion, for comparative purposes. Each duct system, save for a few details, presented similar morphological features in all species. The epithelial surface of the rete testis was regular and each cell bore a single cilium, as well as numerous, or in some parts, very few, short, regular microvilli. Each of the Types I and II non-ciliated cells of the proximal and efferent ducts displayed abundant, moderately long and regular microvilli, and a solitary cilium. The ciliated cells exhibited tufts of cilia. The Type III non-ciliated cell of the connecting and epididymal ducts exhibited a solitary cilium, and numerous microvilli which were intermediate in length between those of the rete testis and those of the efferent ducts. Vascular perfusion of the avian epididymal tissue was the superior method of fixation because it minimised the developments of fixation artefacts. Apocrine secretion did not appear to occur in the epididymis of these birds as the apical blebs of Types I, II and III cells, which have previously been reported, only manifest in this study in inadequately fixed tissues, and were therefore viewed as being artefacts. The present findings suggest that the current terminology, as applied to the avian epididymis, be retained.     

The surface features of the epithelial lining of the ducts of the epididymis of the ostrich (Struthio camelus)

The luminal appearance of the various ducts of the epididymis of the ostrich was studied by scanning electron microscopy in tissues fixed by immersion in glutaraldehyde. The ductal types were similar to those previously described for some other species of birds. Numerous short microvilli, as well as a single cilium, projected from the apical surface of the rete testis cell. The ciliated cells of the efferent ductules projected tufts of cilia into the ductal lumen, while the non-ciliated cells bore short microvilli. The connecting and epididymal ducts were lined by a columnar cell type whose apical surface bore uniformly distributed microvilli and a single, centrally situated cilium. The spermatozoa found in all ducts of the epididymis bore a distal cytoplasmic droplet. This observation has implications for the maturational process in the ostrich spermatozoon in the epididymis. The surface features of the ducts, except for a few noteworthy differences, were generally similar to those previously described for the male domestic fowl, turkey and duck.     

Structural and immunohistochemical features of the epididymal duct unit of the ostrich (Struthio camelus)

The epididymal duct unit, comprising the ductus conjugens, ductus epididymidis and ductus deferens, was studied histologically, ultrastructurally and immunohistochemically in five sexually mature and active birds. The main morphological features of the pre-dominant non-ciliated (type III) cell of the epithelial lining of this duct unit include, but are not limited to, a moderately abundant smooth or sparsely granulated endoplasmic reticulum, electron-dense secretory granules and numerous mitochondria in the supranuclear zone of the cytoplasm. A single, large heterogeneous lipid droplet, of unknown function, was characteristically situated immediately proximal to the nucleus. The epithelium is obviously secretory and specifically, of the merocrine, and not apocrine, type of secretion. The epithelium of the epididymal duct unit was only focally and weakly to moderately immunopositive to both actin MF and desmin IF, while the duct unit was immunonegative to cytokeratin and vimentin intermediate filaments. The peritubular muscular layer was moderately to strongly positive to both actin and desmin, and negative to cytokeratins and vimentin.     

Immunolocalization of Androgen Receptor in the Boar Epididymis: the Effect of GnRH Agonist Deslorelin

Epididymides from nine crossbred male pigs [Polish Landrace × (Duroc × Pietrain)] (n = 3 per each group) were used in this study to show whether there are any differences between androgen receptor (AR) distribution along epididymal duct of a GnRH agonist deslorelin-treated boars when compared to the control tissues. The active agent was administered by way of a subcutaneous controlled-release implant containing 4.7 mg deslorelin at 91 or 147 days of age respectively. Boars from two experimental groups and the control group were slaughtered at 175 day of age. Immunolocalization was performed using a polyclonal rabbit antiserum against the AR. In control boars, strong staining for AR was detected in nuclei of the epithelial (principal and basal) and stromal cells, whereas in boars treated with deslorelin the staining was confined to the principal cell nuclei. In those treated for 84 days, AR-immunostaining was weak or the principal cells were negative for the AR. Irrespective of the time from deslorelin insertion all stromal cells were immunonegative. The results demonstrate for the first time the effect of deslorelin on the distribution of the AR in the three regions of the boar epididymis. It is likely that stromal cells are more sensitive than epithelial cells to the regulation of AR expression by androgen. The morphological and functional alterations along the epididymal duct and lack of spermatozoa within the lumen after deslorelin treatment indicate that a potent GnRH agonist is likely responsible for an impairment of the microenvironment created by epididymal cells for sperm maturation and their storage.     

Aquaporin 9 is expressed in the epididymis of immature and mature pigs

Aquaporins (AQPs) are channel proteins that facilitate the transepithelial and bidirectional movement of water. AQP9 is an aquaporin that is expressed in the mammalian epididymis. This water transport contributes to epididymal sperm concentration. This study aimed to examine the morphology of epididymal epithelium in piglets and boars, as well as the expression and immunolocalization of AQP9. The piglets presented an epididymal epithelium in differentiation with principal, basal and apical cells. The cellular population of the epididymal epithelium in boars consisted of principal, basal, apical, clear and narrow cells. The migratory cells known as halo cells were observed in the epididymis of both piglets and boars. AQP9 expression presented differences between piglets and boars. Moderate intensity of AQP9 immunoreaction was observed in the apical border of the epididymal epithelium of the caput and cauda regions in the piglet epididymis. A moderate‐to‐intense reaction for AQP9 was observed in the nuclei of epithelial cells of the three epididymal regions in the boar epididymis. The region of the cauda epididymis showed reactivity for AQP9 also in the apical border of the epithelium. It is believed that the AQP9 is already functional in piglets at only 1 week of age and is more active, playing a pivotal role in the caput and cauda regions of the epididymis. Moreover, the intense AQP9 expression in the apical border of epithelial cells in the cauda region of the boar epididymis suggests a higher performance of AQP9 in this region, where sperm complete their maturation process, stored and concentrated.     

Immunohistochemical study of galectin-3 in mature and immature bull testis and epididymis

Galectin-3, a member of the β-galactoside-binding protein family, has been implicated in mammalian sperm maturation. We examined galectin-3 expression in the testis and epididymis of sexually mature and immature bulls. Western blot analysis showed varying levels of galectin-3 in the bull testis and epididymis, and galectin-3 immunoreactivity was higher in the mature testis and epididymis than in immature organs. Galectin-3 was primarily localized in interstitial cells of the immature bull testis and in the peritubular myoid and interstitial cells of the mature testis. In the immature epididymis head, galectin-3 was primarily in the principal and basal cells of the epithelium. In the mature epididymis head, moderate levels of galectin-3 were detected in the sperm, while low levels were found in the stereocilia, epithelium and connective tissue. In the immature epididymis body, moderate protein levels were detected in the principal cells, while lower levels were found in the basal cells. The mature epididymis body showed moderate levels of galectin-3 immunostaining in the stereocilia and epithelium, but low levels in the connective tissue. In the immature epididymis tail, only low levels of galectin-3 staining were found in the epithelium, whereas the mature epididymis tail showed high levels of galectin-3 in the principal cells, moderate levels in the basal cells and low levels in connective tissue. These findings suggest that galectin-3 expression plays a role in the maturation and activation of sperm in bulls.     

Estrogen and androgen receptor expression in relation to steroid concentrations in the adult boar epididymis

The steroid hormone regulation of the epididymis in a high estrogen producing animal like the boar is not currently understood. To test the hypothesis that the boar epididymis is an estrogen and androgen responsive tissue, the presence of estrogen and androgen receptors, in conjunction with steroid hormone concentrations were investigated in the boar epididymis. Epididymal (caput, corpus, cauda) and testicular samples of boars (1–2.5 years; n = 5) were collected for immunolocalization of estrogen receptor alpha (ER), estrogen receptor beta (ERβ) and androgen receptor (AR). Concentrations of testosterone, estradiol and estrogen conjugates (EC) in the tissue were also determined. AR and ERβ were localized in the principal and basal cells of all three epididymal regions. ER was localized in the principal cells of the caput, some cells of the corpus and was not present in the cauda. Testosterone (p < 0.0001), estradiol (p < 0.0001) and EC (p < 0.005) were significantly lower in the epididymis compared with the testis. The epididymal regions were not significantly different from each other for testosterone (p > 0.15) or estradiol (p > 0.09). EC were significantly higher in the corpus than either the caput (p = 0.003) or cauda (p = 0.002). These results suggest that the boar epididymis is responsive to both estrogens and androgens and that both steroid hormones are important for proper epididymal function. Since testosterone and estradiol concentrations are similar throughout the epididymis, regional differences in steroid hormone regulation are likely due to differences in receptor expression.     

A light and scanning electron microscopic study of the epididymis active state of the endemic Mexican rodent Peromyscus winkelmanni (Carleton) (Rodentia: Muridae)

The macroscopic and microscopic anatomy of the epididymis of the sexually mature Peromyscus winkelmanni (carleton) was examined using light and scanning electron microscopy. The epididymis was divided into three regions: caput, corpus and cauda. The epididymal duct was lined with columnar and cubic epithelium with stereocilia and covered by a muscular connective tissue sheath. Capillaries appear to penetrate directly into the epithelium from the underlying connective tissue in the initial segment. The epididymal epithelium presents four cell types: principal, basal, apical and clear cells. Based on morphological differences (height of epithelial cells, length of the stereocilia, luminal area, larger diameter and spermatic index), the epididymis of P. winkelmanni, presents seven zones. The stereocilia of the epididymal ducts of zones I, II, IV and V are thick and tall, while in zone III they are thin and short. The stereocilia in zone VI are thin, while in zone VII they are short but thick. The secretory products observed in the lumen of the epididymal ducts have vesicular, granular and fibrous form in the seven zones. This study contributes to an understanding of the morphofunctional features of the epididymis in sperm maturation in a species that shows seasonal reproductive activity.     

Immunolocalization of Intermediate Filaments and Laminin in the Oviduct of the Immature and Mature Japanese Quail (Coturnix coturnix japonica)

This study describes the distribution of vimentin, desmin, smooth muscle actin (SMA) and laminin in the oviduct of the immature and mature Japanese quail. The cytoskeletal proteins vimentin, desmin and SMA have been shown to be involved in cellular support, differentiation, migration and contractility. Laminin is a major component of basement membranes. Luminal epithelia in the infundibular and magnal regions of immature and mature birds exhibited strong vimentin immunoreactivity. Luminal epithelial cells exhibiting strong vimentin immunoreactivity were present in the isthmus and shell gland regions of only mature quails. Infundibular glandular grooves displayed strong vimentin immunostaining. In contrast, the glandular epithelia of the magnum, isthmus and shell gland were vimentin immunonegative. Fibroblasts and vascular endothelial cells in the lamina propria of the oviductal regions studied exhibited strong vimentin immunostaining. Smooth muscle cells forming the tunica muscularis and vascular tunica media displayed strong desmin and SMA immunostaining. Strong laminin immunostaining was demonstrated in the basement membranes associated with smooth muscle cells, as well as in the basement membranes underlying the luminal and glandular epithelia. In conclusion, this study has shown that the immunolocalization of desmin, SMA and laminin in the oviduct of the Japanese quail is similar to that in the domestic fowl. However, differences in the immunoexpression of vimentin in the LE of the two avian species were shown to exist. In addition, the study has shown that the immunolocalization of vimentin in the Japanese quail varies depending on the oviductal region, as well as the developmental stage of the oviduct.     

大鸨生殖系统形态结构初步研究

通过对7只不同年龄♂♀体大鸨生殖系统的形态结构解剖发现：大鸨雄性生殖系统由睾丸、附睾、输精管和交配器组成,无真正的阴茎,而具有阴茎体。睾丸一对,黑色、长形、豆状,右侧在前,左侧睾丸略大于右侧。大鸨睾丸从孵化出壳到性成熟无颜色变化,只是体积和重量增长。附睾在幼年时不明显,而在成体发情期时显著,呈前端较大的纺锤形。输精管外观为半透明、黑色弯曲的线状,沿输尿管向后延伸至泄殖腔壁形成突起,即输精管乳头;雌性生殖系统由卵巢和输卵管组成。卵巢和输卵管仅左侧正常发育,右侧输卵管退化为—短白色盲管。左卵巢因卵泡发育而呈葡萄串状。左输卵管在性未成熟时为一直形细管,性发育成熟后有较多弯曲,管径也增大,可分为漏斗部、壶腹部、峡部、子宫和阴道5部分。     

Expression of Occludin in Testis and Epididymis of Wild Rabbits, Lepus sinensis coreanus

Tight junctions (TJs) in inter-Sertoli junctional areas and epididymal epithelia build up the blood–testis barrier (BTB) and the blood–epididymal barrier (BEB), respectively. In this study, the expression of occludin, an integral member of the TJs, was examined in testis and different regions of epididymis of Lepus sinensis coreanus , an Korean wild rabbit species. In testis, intense occludin immunoreactivity was found in the basally located inter-Sertoli junctional area together with diffused immunoreactivity of occludin in the cytoplasm of Sertoli cells. It can be suggested that occludin is one of the robust elements of BTB in seminiferous tubules of rabbit testis. In proximal and distal caput epididymis, occludin immunoreactivity was found in the lateral as well as apical contacts of epithelial cells. In corpus epididymis, intense occludin immunoreactivity was found in the basolateral as well as apical contacts of epithelial cells together with cytoplasmic signal. In cauda epididymis, occludin immunoreactivity in luminal epithelia was relatively strong but largely found in the cytoplasm. This suggests that intriguing regulatory mechanisms differentially recruit occludin to the TJ in the different regions of epididymal epithelia. The differences in the subcellular localization as well as expression levels of occludin among the epididymal segments may reflect differential paracellular permeability of epithelia along the epididymal tubules and be correlated with sperm maturation in rabbit. In Western blot, a major form of occludin was MW 62 kDa together with small fragments of MW 34–39 kDa in testis and epididymis, suggesting the peptide cleavage of occludin. This is the first report on the molecular nature of TJs in a wild rabbit testis and epididymis.     

Morphological and glycohistochemical studies on the epididymal region of the Sudani duck (Cairina moschata)

In this study, the epididymal region of the Sudani duck was investigated using histological and lectin histochemical methods. Morphologically, the epididymal region of the Sudani duck is composed of extratesticular rete testis, proximal and distal efferent ductules, a short connecting duct, and epididymal ducts. Morphometric analysis of the epididymal region of Sudani duck revealed that the efferent ductules predominate in relation to the epididymal ducts. The distribution of sugar moieties within the epididymal region of the Sudani duck was investigated using ten different fluorescein isothiocyanate (FITC) conjugated lectins. In the rete testis epithelium, only PHA-L showed a positive reaction. Efferent ductules in contrary exhibited a wide range of lectin affinity whereas six positive lectins (Con A, LCA, PNA, WGA, PHA-L, PHA-E) were observed. In the connecting and epididymal ducts, four lectins (Con A, WGA, PHA-L, PHA-E) were also detected. GSA-I, UEA-I, and LTA were at all not evident in the epididymal region of the Sudani duck. In conclusion, the correlation between the large areas of the epididymal region occupied by the efferent ductules and the wide range of sugar affinity of this portion may confirm the speculation that efferent ductules might be the primary site of fluid reabsorption in the epididymal region of Sudani duck.     

Immunohistolocalization of carbonic anhydrase isoenzymes (CA-I, -II and -III ) in canine epididymis

The immunolocalization of the efferent duct and the epididymis in canine was firstly examined using an the immunohistochemical method with the canine carbonic anhydrase (CA) -I, CA-II and CA-III antisera. The efferent duct was immunonegative for all present canine CA antisera. However, some slender shaped epithelial cells in the head and body segments of the epididymal duct were intensely reacted to the CA-II antiserum. These results suggested that the CA-II might be controlled in the luminal environment in the head and body segments of the canine epididymis by the proton and bicarbonate balance for the maintenance of the spermatozoal stability and movement.