Difference of fertilizing capacity between testicular sperm and vas deferens sperm in Cynops pyrrhogaster

The fertilizing capacity was compared between testicular and vas deferens sperm in Cynops pyrrhogaster. The testicular sperm was not capable of fertilizing jelly eggs. In contrast, the vas deferens sperm was already capable of fertilizing the newt jelly eggs. There was no inhibitory factor for fertilizing jelly eggs in the testis. These results suggest that the testicular sperm is immature as to the fertilizing capacity. The testicular sperm gained the fertilizing capacity for the jelly eggs by treatment with Holtfreter's solution or 1/20 strength Holtfreter's solution. The treatment may promote the step of maturation to achieve the fertilizing capacity. The treated testicular sperm did not fertilize dejellied eggs, although vas deferens sperm fertilized dejellied eggs. Therefore, the maturation state of the treated testicular sperm is different from that of vas deferens sperm. Newt sperm may be matured within the vas deferens, as the newt does not have an organ like the mammalian epididymis.     

Light and electron microscopic studies on the seminal secretions and the vas deferens of the penaeiodean shrimp,Sicyonia ingentis

Unlike the other penaeiodean shrimp, the ridge back shrimp, Sicyoniaingentis does not produce a spermatophore, but transfers sperm suspended in seminal plasm. This paper reports on the histomorphology and ultrastructure of the vas deferens with reference to its functional role in secreting the sperm bearing materials. The vas deferens is divisible into proximal secretory, mid storage and distal ejaculatory regions. The epithelial cells lining the proximal vas deferens are comprised of secretory and absorptive cell types. The loose sperm cells found in the lumen of this region are in an immature condition, and are agglutinated into a compact mass with signs of spermiogenesis in the mid vas deferens. The epithelial cells lining the mid vas deferens are short flattened cells. The distal vas deferens is ensheathed by muscular fibres. The inner epithelial cells are highly secretory and contain numerous microvilli at the luminal end. The sperm cord gets liquefied in this region facilitating the transfer of sperm in liquid form to the female during mating.     

Sperm morphology and arrangement along the male reproductive tract of the butterfly Euptoieta hegesia (Insecta: Lepidoptera)

Summary

The present study was undertaken to describe the morphological and organizational modifications that occur in apyrene and eupyrene spermatozoa along the male adult reproductive tract of the butterfly, Euptoieta hegesia. Testis, vas deferens, vesicula seminalis and ductus ejaculatorius were studied by transmission electron microscopy. In the testis, both sperm types are organized into cysts; apyrene sperm are devoid of extracellular structures while eupyrene ones have lacinate and reticular appendages. In the testis basal region, both sperm pass through an epithelial barrier and lose their cystic envelope. The eupyrene morphological and organizational modifications are more drastic than the apyrene ones. From the vas deferens to the ductus ejaculatorius, apyrene sperm are dispersed in the lumen and acquire several concentric layers that are formed by the folding of their abundant cell membrane. The apyrene distribution observed here suggests that their functions include eupyrene transportation. Eupyrene sperm, however, remain aggregated along the tract. In the vas deferens, they are covered by a filamentous material that develops into a homogeneous matrix surrounding the spermatozoa coat in the vesicula seminalis and the ductus ejaculatorius. Eupyrene sperm undergo complex morphological changes that include the loss of lacinate appendages and the formation of a dense and heterogeneous extracellular coat. The formation of the matrix and the coat in eupyrene extratesticular sperm is related to the loss of lacinate appendages. These changes are in general extracellular and are probably important for sperm maturation.     

日本沼虾输精管的结构及其在精荚形成中作用的研究

应用光镜和透射电镜技术研究了日本沼虾输精管的结构及其在精荚形成中的作用。结果表明,日本沼虾输精管从形态结构上可分为近端输精管、卷曲输精管、远端输精管和膨大的远端输精管四部分。各部分的管壁皆由分泌上皮、基膜、肌肉层和结缔组织构成,其中分泌上皮包括高度明显不同的低柱状上皮和高拄状上皮两部分。输精管各部分管腔内含有处于不同形成阶段的精荚。进入近端输精管内的精子被支撑在一种嗜酸性基质中。近端输精管的分泌物主要帮助形成精子团,同时形成精荚壁的极小部分。卷曲和远端输精管分泌形成精荚壁的绝大部分,其分泌物由细胞顶端通过外排作用和顶泌机制分泌产生。膨大的远端输精管具有贮存精荚的作用,其分泌上皮也通过外排作用和顶泌机制产生分泌物包裹在已基本形成的精荚外侧,管壁肌肉层在雌雄交配时将管腔内的精荚切割成适宜长度并排出体外。       

Circadian rhythm of glycoprotein secretion in the vas deferens of the moth, Spodoptera littoralis

Background  

Reproductive systems of male moths contain circadian clocks, which time the release of sperm bundles from the testis to the upper vas deferens (UVD) and their subsequent transfer from the UVD to the seminal vesicles. Sperm bundles are released from the testis in the evening and are retained in the vas deferens lumen overnight before being transferred to the seminal vesicles. The biological significance of periodic sperm retention in the UVD lumen is not understood. In this study we asked whether there are circadian rhythms in the UVD that are correlated with sperm retention.     

The vas deferens of the spider crab,Libinia emarginata

Sperm enter the anterior vas deferens individually in the spider crab male. There they become surrounded by secretion products from the cells of the vas deferens, and are compartmentalized into spermatophores of varying size. The anterior vas deferens can be divided into three regions. The epithelium of the anterior vas deferens varies regionally from low to high columnar. The cytoplasm contains vast arrays of rough endoplasmic reticulum and Golgi complexes but few mitochondria. Intercellular spaces contain septate junctions, gap junctions and vesicles. Once the spermatophores have been formed in the anterior vas deferens, they are moved posteriorly to the middle vas deferens where they are stored and surrounded by seminal fluids. The epithelial cells of the middle vas deferens contain large amounts of rough endoplasmic reticulum and Golgi complexes. Numerous micropinocytotic vesicles appear, forming at the cell surface and within the apical cytoplasm. Their suggested function is the resorption of secretion products of the anterior vas deferens which initiated compartmentalization of the spermatozoa into spermatophores. The posterior vas deferens functions primarily as a storage center for spermatophores until they are released at the time of copulation. Seminal fluid surrounding the spermatophores is produced in this region as well as in the middle vas deferens. The cells of this region contain vast arrays of vesicular rough endoplasmic reticulum and Golgi complexes. The cells are multinucleate. Microtubules are numerous throughout the length of the cells and appear to insert on the plasma membrane.     

Circadian rhythm of sperm release in the gypsy moth,Lymantria dispar: ultrastructural study of transepithelial penetration of sperm bundles

Release of mature bundles of spermatozoa from the testis into the vas deferens is a critical but poorly understood step in male insect reproduction. In moths, the release of sperm bundles is controlled by a circadian clock which imposes a temporal gate on the daily exit of bundles through the terminal epithelium-a layer of specialized epithelial cells separating testis follicles from the vas deferens. The sequence of cellular events associated with the daily cycle of sperm release was investigated by scanning and transmission electron microscopy. In the hours preceding sperm release, there is a solid barrier between the testis and the vas deferens formed by the interdigitation of cytoplasmic processes of adjacent terminal epithelial cells. At the beginning of the sperm release cycle, sperm bundles protrude through this barrier while the terminal epithelial cells change their shape and position relative to the bundles. Subsequently, the cyst cells enveloping the sperm bundles break down and spermatozoa move out of the testis through the exit channels formed between the epithelial cells. Afterwards, cyst cell remnants and other cellular debris are released into the vas deferens lumen, and the epithelial barrier is reconstructed due to phagocytic activity of its cells. These data provide a foundation on which to build an understanding of the cellular mechanisms of clock-controlled sperm release in insects.     

Fate and composition of cytopiasmic droplet of hamster epididymal spermatozoa

Observations on sperm maturation in the hamster (Mesocricetus auratus) epididymis revealed that the cytoplasmic droplet migrates from the proximal position of the sperm flagellum to the end of the midpiece. This process begins in the testis or vas efferens and ends in the cauda region of the epididymis. A study of different regions of the epididymis and vas deferens demonstrated that the cytoplasmic droplet is not released from the sperm into the luminal fluid. An ultrastructural study of the cytoplasmic droplet demonstrated changes in its morphology as its position moved distally along the midpiece. Membranous components called saccules or vesicles, believed to be remnants of the Golgi apparatus present in the cytoplasmic droplet, changed their morphology during the migration process. Inclusion bodies within vesicles were released to the lumen at the levels of the cauda epididymis and the vas deferens. © 1994 Wiley-Liss, Inc.     

Morphological changes in the vas deferens and expression of the cystic fibrosis transmembrane conductance regulator (CFTR) in control, deltaF508 and knock-out CFTR mice during postnatal life

The morphology of the mouse vas deferens still undergoes major changes from birth to 40 days of age, such as differentiation of the mesenchymal cells into fibroblasts and muscle cells, differentiation of the epithelium into basal and columnar epithelial cells, development of stereocilia, and the appearance of smooth endoplasmic reticulum organised in fingerprint-like structures or parallel, flattened saccules. In mutant homozygous DeltaF508 (DeltaF/DeltaF) and knock-out (cf/cf) CFTR mice, strain 129/FvB and 129/C57BL-6, respectively, a similar development occurred until the age of 20 days. At 40 days, however, the lumen was filled with eosinophilic secretions, and sperm cells were absent in the majority of the animals examined, although sperm production in testis and epididymis appeared to be normal. CFTR was localised in the apical membrane and cytoplasm of the vas deferens epithelium from 40 days on but could not be detected in the vas deferens before 20 days or in mutant adult CFTR mice as expected. Western blots of membrane preparations showed that the mature form of CFTR was present in vas deferens and testis but absent in seminal vesicles. Our results suggest that the function of CFTR is probably essential after 20 days in the vas deferens and that its absence or dysfunction may result in a vas deferens with a differentiated epithelium but a collapsed lumen, which could at least temporarily delay the transport of spermatozoa. These observations contrast with those made in the overall majority of CF patients. Mol. Reprod. Dev. 55:125-135, 2000.     

Effects of a single ethanol injection into the vas deferens on the testicular function of rats.

1. A new approach to rapid male sterilization has been studied by giving a single injection of 95% ethanol directly into the vas deferens. It produced an effective block in the lumen. The mating exposure test showed that the males were sterile. The sperm granulomas at the site of vas injection were confirmed. 2. Ethanol injection in the vas deferens caused an atrophy of the testes. Extensive necrosis and exfoliation of the seminiferous elements were conspicuous. 3. Decrease in testicular weight, seminiferous tubule diameter and RNA and sialic acid levels after 4 weeks of vas injection were associated with the histological evidence for severe degeneration of spermatogenic elements. The protein contents of testis, epididymides and seminal vesicles did not change. 4. Testicular cholesterol, total lipids and alkaline phosphatase activity was increased. 5. Low sialic acid levels in the testis, epididymides and seminal vesicles of vas-injected rats indicated an inhibition of androgen production, which was further reflected in reduced nuclear diameters of leydig cells.     

Ultrastructure and role of the lobster vas deferens in spermatophore formation: The proximal segment

We have examined the anatomy of the vas deferens of the lobster Homarus americanus and have described the structure of the proximal vas deferens (segments one and two). The two tubes of segment one descend from the testes and gradually merge into segment two. The epithelium of segment one has synthetic activity and appears to contribute to the sperm-supporting matrix by exocytotic release of granules through its apical surface. The epithelium of segment two is also highly synthetic and secretes the primary spermatophore layer and part of the intermediate layer that surround the sperm mass. The trifoil shape of the extruded spermatophore is established through a change in height of some of the cells lining the lumen in segment two. Connective tissue and circular bands of striated muscle surround the epithelium of both segments.     

Functional morphology of the male reproductive system in Callichirus major (Crustacea: Decapoda: Axiidea): Evidence of oocytes in the gonad

Callichirus major inhabits the intertidal region of marine ecosystems and it is frequently used as live bait for fishing. This study aimed to describe the functional anatomy of the male reproductive system by microscopic techniques. The animals were collected along the Corujão beach, Piuma—ES, Brazil, and, in laboratory, the males were classified into two phases: immature (IM) and developed (DE) based on the macroscopic characteristics of the gonads. The gonad and vas deferens were dissected for histological routine and histochemical tests. Histologically, it was noted that in both phases, the more distal region of gonads has ovarian characteristics, showing developing oocytes. Also, different male germ cells were identified: spermatogonium (SPG), spermatocytes I and II (SPTCI, SPTCII), initial and final spermatid (IS, FS) and sperm (SPZ). Accessory cells with spherical or pyramidal nuclei were also present inside the testicular lobules. According to the vas deferens structure, three regions can be characterized: proximal (PVD), middle (MVD) and distal (DVD). In the lumen of the vas deferens, a spermatophoric matrix highly reactive for histochemical tests was observed. The presence of female germ cells in males suggests the occurrence of intersexuality or hermaphroditism in this species.     

Ultrastructure and function of the seminal vesicle of Bittacidae (Insecta: Mecoptera)

The fine structure of the seminal vesicle and reproductive accessory glands was investigated in Bittacidae of Mecoptera using light and transmission electron microscopy. The male reproductive system of Bittacidae mainly consists of a pair of testes, a pair of vasa deferentia, and an ejaculatory sac. The vas deferens is greatly expanded for its middle and medio-posterior parts to form a well-developed seminal vesicle. The seminal vesicle is composed of layers of developed muscles and a mono-layered epithelium surrounding the small central lumen. The epithelium is rich in rough endoplasmic reticulum and mitochondria, and secretes vesicles and granules into the central lumen by merocrine mechanisms. A pair of elongate mesodermal accessory glands opens into the lateral side of the seminal vesicles. The accessory glands are similar to the seminal vesicle in structure, also consisting of layers of muscle fibres and a mono-layered elongated epithelium, the cells of which contain numerous cisterns of rough endoplasmic reticulum and mitochondria, and a few Golgi complexes. The epithelial cells of accessory glands extrude secretions via apocrine and merocrine processes. The seminal vesicles mainly serve the function of secretion rather than temporarily storing spermatozoa. The sperm instead are temporarily stored in the epididymis, the greatly coiled distal portion of the vas deferens.     

High‐resolution imaging of the actin cytoskeleton and epithelial sodium channel,CFTR, and aquaporin‐9 localization in the vas deferens

Vas deferens is a conduit for sperm and fluid from the epididymis to the urethra. The duct is surrounded by a thick smooth muscle layer. To map the actin cytoskeleton of the duct and its epithelium, we reacted sections of the proximal and distal regions with fluorescent phalloidin. Confocal microscopic imaging showed that the cylinder‐shaped epithelium of the proximal region has a thick apical border of actin filaments that form microvilli. The epithelium of the distal region is covered with tall stereocilia (13–18 µm) that extend from the apical border into the lumen. In both regions, the lateral and basal cell borders showed a thin lining of actin cytoskeleton. The vas deferens epithelium contains various channels to regulate the fluid composition in the lumen. We mapped the localization of the epithelial sodium channel (ENaC), aquaporin‐9 (AQP9), and cystic fibrosis transmembrane conductance regulator (CFTR) in the rat and mouse vas deferens. ENaC and AQP9 immunofluorescence were localized on the luminal surface and stereocilia and also in the basal and smooth muscle layers. CFTR immunofluorescence appeared only on the luminal surface and in smooth muscle layers. The localization of all three channels on the apical surface of the columnar epithelial cells provides clear evidence that these channels are involved concurrently in the regulation of fluid and electrolyte balance in the lumen of the vas deferens. ENaC allows the flow of Na⁺ ions from the lumen into the cytoplasm, and the osmotic gradient generated provides the driving force for the passive flow of water through AQP channels.     

Cyclic changes in the testis of the brook stickleback Eucalia inconstans (Kirtland)

The cyclic changes in the testis of the five-spined stickleback Eucalia inconstans (Kirtland) were studied histologically. Specimens were trapped between July 1965 and July 1967 in a shallow pond near London, Ontario. A three-dimensional microscopic study showed a main vas deferens and a system of primary, secondary and tertiary tubules. The testis cycle was divided into seven arbitrary stages. Spawning takes place from mid-April to mid-July. This is followed by the division of primary spermatogonia which are located along the walls of the tubules, producing cysts of spermatogonia enclosed in connective tissue which is surrounded by a thin epithelium. Both primary and secondary spermatocytes develop within these cysts. Breakdown of the cysts occurs with the development of spermatids and spermiogenesis occurs while spermatids are free in the tubules. Over-wintering of mature sperm takes place. Development of mature sperm from primary spermatogonia takes about 156 days. Germinal epithelium is absent but primary germ cells are believed to be those cells occupying the spaces between the tubules of the testis. No tissue which might be implicated in hormone production was observed. Phagocytic invasion of the testis has been studied. Massive infiltration by phagocytes is believed to be responsible for the sudden increase in testis weight observed during spawning. These cells ingest sperm nuclei and groups of them have been observed in the lumen of the tubules and the vas deferens, probably on their way out of the body.     

日本沼虾雄性生殖系统的研究：Ⅲ.输精管内精荚的结构与形成

于光镜和电镜下研究日本沼虾输精管内精荚的结构与形成。结果显示：粗荚呈索状,由精子群、精荚基质、粘液团和荚壁组成;精荚基质与粘液团内均含有交织的纤丝,其中散布着絮状泡和同心圆形泡,精荚壁呈“Ｃ”型,单层,由致密纤丝、絮状泡和沟形的网状结构组成,包裹精子群和粘液团;前、中、后输精管的上皮细胞均具合成、分泌精荚形成物质的功能。     

Mouse testicular and sperm cell development characterized from birth to adulthood by dual parameter flow cytometry

Dual parameter flow cytometry was used to investigate cellular changes in male germinal tissue during normal postpartum maturation in B6C3F1/J mice. Animals were killed at 2-day intervals from 2 to 42 days postpartum and at 48, 64, 72, 93 and 100 days postpartum. Testicular, cauda epididymis and vas deferens cell suspensions were stained with the metachromatic fluorochrome acridine orange and measured by flow cytometry for red and green fluorescence levels after excitation by blue laser light. Intensities of red and green fluorescence reflect amounts of single- and double-strand nucleic acid sites available for acridine orange staining, respectively, and were used to classify cells on the basis of ploidy level, RNA content, and chromatin structure, as defined by susceptibility to acid denaturation of DNA in situ. Sperm from cauda epididymis and vas deferens were examined by light microscopy to determine frequency of abnormal sperm head morphology. Fluorescence data derived from acridine orange-stained testicular cells quantified the sequential changes in 1) proportions of haploid, diploid and tetraploid cell types during the first round of spermatogenesis, and 2) proportions of round, elongating, and elongated spermatids during the first round of spermiogenesis. Ratios of the three major testicular populations (haploid, diploid, and tetraploid) reached adult levels by 48 days postpartum. Sperm cells were first detected in the cauda epididymis and vas deferens on 30 and 36 days postpartum, respectively. Early sperm populations, compared to adult sperm, exhibited up to 89% abnormalities in sperm head morphology that correlated with significant levels of abnormal chromatin structure. Percentage of sperm head abnormalities and chromatin structure in the cauda epididymis and vas deferens approached normal adult levels by 42 and 48 days postpartum, respectively.     

Maturation of guinea pig sperm in the epididymis involves the modification of proacrosin oligosaccharide side chains

Proacrosin from guinea pig cauda epididymal sperm has a lower molecular weight compared with the testicular zymogen. In this study, we have examined the structural basis of this change and where the conversion in proacrosin molecular weight occurs during sperm maturation. Immunoblotting of trifluoromethanesulfonic acid-deglycosylated testicular and cauda epididymal sperm extracts with antibody to guinea pig testicular proacrosin demonstrated that the polypeptide backbones of proacrosins from the testis and cauda epididymal sperm had the same molecular weights (approximately 44,000). Keratanase, an endo-beta-galactosidase specific for lactosaminoglycans, partially digested testicular proacrosin but had no effect on proacrosin from cauda epididymal sperm. In extracts of testis, caput epididymis, and corpus epididymis analyzed by immunoblotting, anti-proacrosin recognized a major antigen with an apparent molecular weight (Mr) of 55,000, although a 50,000-Mr minor antigen began to appear in the corpus epididymis. By contrast, extracts of cauda epididymis, vas deferens, and cauda epididymal sperm had the 50,000 Mr protein as the only immunoreactive antigen. By enzymography following electrophoresis, the major bands of proteolytic activity in extracts of testis, caput epididymis, and corpus epididymis had 55,000 Mr. A band of protease activity with 55,000 Mr also appeared in extracts of the corpus epididymis. However, the most prominent bands of proteolytic activity in cauda epididymis, vas deferens, and cauda epididymal sperm had 50,000 Mr. In addition, two other major protease activities were detected with 32,000 and 34,000 Mr; the relationships of these proteases to proacrosin are unclear. From these results, we conclude that the oligosaccharides of proacrosin are altered during epididymal transit and that this modification occurs in the corpus epididymis.(ABSTRACT TRUNCATED AT 250 WORDS)     

东方扁虾雄性生殖系统的解剖学和组织学研究

东方扁虾雄性生殖系统由精巢、输精管及雄性生殖孔三部分组成,输精管可分为前、中、后三段。精巢由卷绕的前、后收集管及持靠其上的许多生精腺囊所组成。同一腺囊内的精细胞发生基本同步,而不同腺囊内则可以不同步。收集管的主要功能是将精细胞团输送至输精管。精荚在输粗管内运行时一直进行着精子的形成过程,直至精子成熟。位于输精管末段不肌层外的索带状细胞团被认为是造雄腺。