Morphology of gonoducts and male genital papilla, in the bluehead wrasse: implications and correlates on the control of gamete release

In the coral reef fish Thalassoma bifasciatum , males vary the number of sperm they release in successive spawnings with individual females in accordance with female body and clutch size. The morphology and histological structure of the male genital papilla, sperm duct, oviduct and surrounding musculature were examined in an effort to elucidate the mechanism permitting control of the number of gametes released during mating. In males, urinary and genital ducts pass separately through a common urogenital papilla and are associated with a striated sphincter muscle and a pair of thin, smooth ligament muscles arising from the first proximal anal fin radial and passing laterally around the sperm duct and oviduct. Within the papilla, the sperm duct resembles a narrow funnel whose inner walls contain longitudinal folds or septa protruding into the lumen of the duct. Dorsal to the papilla, the sperm duct enlarges and is divided into numerous, open chambers by irregular, longitudinal trabeculae. The wall of the duct and the trabeculae contain flat epithelium, smooth muscle and loose connective tissue. In females, the oviduct contains no trabeculae and is not divided into chambers. The ligament muscles are more thoroughly embedded in the sphincter muscle of the rectum than in males. Some ways in which these structures might control gamete release are suggested.     

Complex genital system of a haplogyne spider (Arachnida, Araneae, Tetrablemmidae) indicates internal fertilization and full female control over transferred sperm

The female genital organs of the tetrablemmid Indicoblemma lannaianum are astonishingly complex. The copulatory orifice lies anterior to the opening of the uterus externus and leads into a narrow insertion duct that ends in a genital cavity. The genital cavity continues laterally in paired tube-like copulatory ducts, which lead into paired, large, sac-like receptacula. Each receptaculum has a sclerotized pore plate with associated gland cells. Paired small fertilization ducts originate in the receptacula and take their curved course inside the copulatory ducts. The fertilization ducts end in slit-like openings in the sclerotized posterior walls of the copulatory ducts. Huge masses of secretions forming large balls are detectable in the female receptacula. An important function of these secretory balls seems to be the encapsulation of spermatozoa in discrete packages in order to avoid the mixing of sperm from different males. In this way, sperm competition may be completely prevented or at least severely limited. Females seem to have full control over transferred sperm and be able to express preference for spermatozoa of certain males. The lumen of the sperm containing secretory balls is connected with the fertilization duct. Activated spermatozoa are only found in the uterus internus of females, which is an indication of internal fertilization. The sperm cells in the uterus internus are characterized by an extensive cytoplasm and an elongated, cone-shaped nucleus. The male genital system of I. lannaianum consists of thick testes and thin convoluted vasa deferentia that open into the wide ductus ejaculatorius. The voluminous globular palpal bulb is filled with seminal fluid consisting of a globular secretion in which only a few spermatozoa are embedded. The spermatozoa are encapsulated by a sheath produced in the genital system. The secretions in females may at least partly consist of male secretions that could be involved in the building of the secretory balls or play a role in sperm activation. The male secretions could also afford nutriments to the spermatozoa.     

Morphological evidence for limited sperm production in the enigmatic Tasmanian cave spider Hickmania troglodytes (Austrochilidae,Araneae)

The male reproductive systems of spiders are highly diverse in structure across all major spider taxa. Little is known about this organ system in basal araneomorph spiders, especially Austrochiloidea; such knowledge is necessary for a more complete understanding of the evolutionary morphology of the male reproductive system in spiders. In the present study, we describe the male reproductive system of an austrochilid spider, the enigmatic troglophilic Tasmanian cave spider Hickmania troglodytes, using light and electron microscopic techniques. The male reproductive system consists of tubular testes leading into convoluted deferent ducts, which are fused close to the genital opening to an unpaired ejaculatory duct. Spermatogenesis occurs only in the subadult testes, whereas adult testes showed neither spermatogenic stages nor any generative tissue in all investigated specimens. The testes of adult males are drastically reduced in size compared with those of subadult males, but the deferent ducts are filled with large numbers of mature spermatozoa. Thus, our data suggest that males of H. troglodytes are sperm‐limited, but not necessarily sperm‐depleted as described for certain orb‐weaving spiders. Due to the absence of generative tissue, limited sperm production is permanent (PSL) and probably has an influence on the reproductive strategies in this species. As nearly no data are available on the life history of H. troglodytes, and in particular information on the phenology of males is lacking, implications of the evolution of PSL in this species are unclear. Nonetheless, our data on other representatives of Austrochilidae (Austrochilus forsteri, Thaida chepu) and Gradungulidae (Progradungula otwayensis) suggest that PSL evolved within Austrochiliodea only in H. troglodytes and might be an adaptation to its troglophilic lifestyle.     

Genital structures in the entelegyne widow spider Latrodectus revivensis (Arachnida; Araneae; Theridiidae) indicate a low ability for cryptic female choice by sperm manipulation

The female genital structures of the entelegyne spider Latrodectus revivensis are described using semithin sections and scanning electron microscopy. Apart from the tactile hairs overhanging the opening of the atrium, the contact zones of the female epigynum are devoid of any sensilla, indicating that the female does not discriminate in favor or against males due to their genital size or stimulation through copulatory courtship. The dumb-bell shape and the spatial separation of the entrance and the exit of the paired spermathecae suggest that they are functionally of the conduit type. Not described for other entelegyne spiders so far, the small fertilization ducts originating from the spermathecae of each side lead to a common fertilization duct that connects the spermathecae to the uterus externus. During oviposition, it is most likely that spermatozoa are indiscriminately sucked out of the spermathecal lumina by the low pressure produced by the contraction of the muscle extending from the epigynal plate to the common fertilization duct. As no greater amounts of secretion are produced by the female during oviposition, and no activated sperm are present within the female genital tract, the secretion produced by the spermathecal epithelium does not serve in displacement or (selective) activation of spermatozoa. These findings suggest that female L. revivensis are not able to exert cryptic female choice by selectively choosing spermatozoa of certain males.     

Morphological and functional adaptations of the female reproductive system in Veigaiidae (Acari: Gamasida) and implications regarding the systematic position of the family

Veigaiidae are predatory gamasid mites with a controversial systematic position. Some authors see a close relationship with Parasitina, others with Dermanyssina. Since the morphology of the genital system is of high relevance in terms of the systematics of Gamasida, we have carefully studied the ultrastructure of the female reproductive system. It consists of two parts, one which accepts spermatozoa (sperm access system), and the other which produces and delivers eggs. Since we have already published a detailed account of the sperm access system we add only some further information here on that system and focus instead on egg production and delivery. The unpaired gonad is divided into a germinal and a nutritive region, the latter of which is a compact structure as in Parasitina and does not show lateral arms as seen in most studied Dermanyssina. The oviduct (uterus, vaginal duct) is an unpaired structure that terminates in a vagina (genital atrium) covered by the genital plate. Two small vaginal glands open into the vagina, which is provided with a peculiar interlocking system. First observations on spermatozoa found in one female reveal similarities with those of Parasitina. Our results are discussed under morphological aspects and compared with other gamasid mites. In conclusion, the veigaiids show some peculiar features that are shared either with Parasitina or with Dermanyssina. These observations make it difficult to simply assume that the Veigaiidae belong either to the Dermanyssina or to the Parasitina. They appear instead to comprise an intermediate entity.     

Double spermatogenesis in Chelicerata

Sperm dimorphism is a rare phenomenon in Chelicerata. Until now, it was known only from three species of the opilionid genus Siro (Sironidae, Cyphophthalmi). Fertilizing (eusperm) and nonfertilizing spermatozoa (parasperm) develop in the same cyst and are thus sister cells. The fine structure of the spermatozoa of two species has been examined and is compared here. In contrast to Siro rubens, S. duricorius spermatozoa lack an acrosomal complex. Both sperm types produce a transitional process, a more or less modified flagellum, which is later retracted. Hence, the spermatozoa are aflagellate. Eusperm and parasperm of all three species form highly ordered sperm balls that are stored in the deferent duct. Reviewing and adding new results about the sperm dimorphism in this arachnid taxon provides the basis for some considerations of another enigmatic morphological character found in Uropygi and Amblypygi, i.e., the tubular accessory genital glands that show holocrine extrusion. These glands are suggested to represent modified, infertile derivatives of the testis anlage. Their secretion is produced in a way reminiscent of a strongly degenerated spermatogenesis. Consequently, these products may be regarded as strongly degenerated germ cells representing a line of germ cell development, which has been separated very early in spermatogenesis from the usual line leading to fertilizing sperm cells. This further, although less evident, case of probable dichotomous germ cell development is discussed with respect to the controversial phylogenetic-systematic relationships between Uropygi (Thelyphonida and Schizomida), Amblypygi, and Araneae.     

Female genitalia of goblin spiders (Arachnida: Araneae: Oonopidae): a morphological study with functional implications

Abstract. Fine morphological details of the genitalia have large potential consequences for the understanding of the reproductive biology of a particular species, especially when mating behavioral studies are difficult to conduct. Oonopidae are a highly diverse spider family comprising a variety of species with complex female reproductive systems, which may have evolved under sexual selection by cryptic female choice. The present study describes the female genitalia of five oonopid species belonging to both conventionally recognized subfamilies by means of semi‐thin sections and scanning electron microscopy. In addition, the male palps are briefly described. The organization of the female genitalia in Scaphiella hespera and Scaphiella sp. resembles the entelegyne type. A chitinized canal connects the receptaculum, where sperm are stored, with the uterus. Sperm are also present in the uterus and the canal is suggested to function as fertilization duct. The genitalia of the parthenogenetic species Triaeris stenaspis are surprisingly complex. A large sac with glands is proposed to represent the equivalent of a receptaculum in sexually reproducing females. In females of Opopaea recondita, sperm are stored in a bulge derivating from the uterus. Contractions of muscles attached to the bulge may lead to sperm dumping. The uterus can be closed by a sclerite in its anterior wall. The receptacula of females of Stenoonops reductus are joined together and contain masses of spermatozoa. Additional sperm were found in the receptacula connection suggesting that fertilization takes place there. The male palps of all the investigated species, except for S. hespera, seem to lack a distincly sclerotized sperm duct. Spermatozoa and secretions are stored in a large reservoir inside the genital bulb surrounded by glandular epithelium.     

Seasonal reproduction of yellowish myotis,Myotis levis (chiroptera: Vespertilionidae), from a Neotropical highland

With a nearly global distribution the vespertilionid bat Myotis represents one of the most exceptional examples of adaptive radiation among mammals. We investigated the reproductive activity of the vespertilionid bat yellowish myotis, Myotis levis, from a highland area in Southeastern Brazil. The data were obtained through histological analyses of the male and female genital systems from February 2010 to May 2011. The testes of the adult yellowish myotis showed seasonal morphological characteristics which were categorized in the following stages: rest, maturing, mature, and mating. Rest and maturing males were recorded throughout the rainy season (October‐March). In the rest stage no spermatogenesis was observed and the epididymal duct was devoid of spermatozoa. Maturing individuals had started spermatogenesis and few spermatozoa were found in the epididymal duct. Mature males were found toward the end (February‐March) of the rainy season, when full spermatogenic activity was recorded and spermatozoa were packed in the epididymal duct. Although not recorded, mating probably occurred in the middle of the dry season (April–September) when the cauda epididymis was enlarged and packed with sperm. The spermatozoa remained stored in the cauda epididymis for at least three months when the testes entered into regression. The ovaries showed all types of ovarian follicles throughout the study period except mature follicles which were registered only in July (mid‐dry season). Lactating females were captured in the beginning of the rainy season. The seasonal reproductive characteristics of the yellowish myotis from this Neotropical highland area were similar those of epididymal sperm‐storing temperate vespertilionids. J. Morphol. 274:1230–1238, 2013. © 2013 Wiley Periodicals, Inc.     

Morphology of the reproductive tract and acquisition of sexual maturity in males of Potamotrygon magdalenae (Elasmobranchii: Potamotrygonidae)

The purpose of this study was to describe the structure of the reproductive tract of males of Potamotrygon magdalenae before, during, and after they acquire sexual maturity, and to establish the first maturity scale for males within the family Potamotrygonidae. The male reproductive tract of P. magdalenae is composed of testes, efferent ducts, epididymides, deferent ducts, seminal vesicles, Leydig, alkaline, and clasper glands, and claspers, all of which are paired and functional. Four sexual maturity stages were established: immature, maturing, reproductively active, and resting. The degree of claspers calcification is also a good indicator of sexual maturity in this species. The testes are lobulated, each lobe contains numerous spermatocysts which are organized in zones and are displaced radially from germinal papillae to the spermatozoa zone where individual spermatozoa are conveyed to the efferent ducts. The epididymis can be regionalized in head, body, and tail; these regions are distinguished by external pigmentation and by the epithelium lining configuration. The tail of the epididymis is connected with the deferent duct and this, in turn, with the seminal vesicle. The spermatozoa are organized in spermatozeugmata which begin to form in the deferent duct; this latter organ is attached laterally at the Leydig gland that is composed by simple glandular units. Irregular and vesicular secretions can be found in the genital ducts. These secretions might be associated with the maturation of the spermatozoa and formation of spermatozeugmata. The male reproductive tract of P. magdalenae is similar to other elasmobranchs; however, two types of primary spermatogonia, an epididymis internally regionalized, and the presence and structure of spermatozeugmata are specific features not yet described in freshwater stingrays. Most of the year, the males were reproductively active, however, few resting adult males occurred during one of the months of the lowest waters. J. Morphol. 276:273–289, 2015. © 2014 Wiley Periodicals, Inc.     

Morphological changes in eupyrene and apyrene spermatozoa in the reproductive tract of the male butterfly Atrophaneura alcinous Klug

Summary

Eupyrene and apyrene spermatozoa are contained in separate cysts in the testis of the butterfly Atrophaneura alcinous. Spermatozoa of both types from various parts of the male reproductive tract were examined with particular reference to their morphological characteristics. All spermatozoa collected from the vas deferens and the vesicula seminalis were found to be immotile under a dissecting microscope. No spermatozoa of either type were recognized in any part of the ejaculatory duct. Within the testis, eupyrene spermatozoa are present in bundles and each spermatozoon has a slender nucleus with an acrosome and a long flagellum containing mitochondrial derivatives. Two kinds of appendages, lacinate and reticular, are present on the surface of the sperm membrane. They are replaced with an extracellular sheath during passage through the vas deferens. In contrast, apyrene spermatozoa have neither nucleus nor acrosome, whereas a cup-shaped structure was found at the sperm tip instead of the acrosome. Unlike eupyrene spermatozoa, they are surrounded by a concentric sheath outside the sperm membrane in the vas deferens. Individual apyrene spermatozoa and coiled bundles of eupyrene spermatozoa were both found to accumulate in the vesicula seminalis before mating. These morphological changes during passage through the male reproductive tract suggests the occurrence of a kind of maturation and capacitation process reminiscent of mammalian spermatozoa.     

Spermatozoa and spermiogenesis of the wolf spider Schizocosa malitiosa (Lycosidae, Araneae) and its functional and phylogenetic implications

The wolf spider Schizocosa malitiosa is a well-known model system for studies on sexual selection in spiders. Despite this, little is known about the morphology of the reproductive system and spermatozoa in this species. In the present study, we investigate the male genital system and sperm cells of S. malitiosa using electron microscopy and provide a computer-based 3D reconstruction of the spermatozoa for the first time for arthropods. In general, the male genital system consists of two long, tube-like testes that lead into convoluted deferent ducts. The ejaculatory duct is enlarged and contains a large quantity of sperm and secretion. As revealed by transmission electron microscopy, only one type of secretion droplet is present in the seminal fluid. The spermatozoa of S. malitiosa resemble an organization known for members of the RTA clade, i.e., with an arrow-shaped acrosomal vacuole partly sunk into the nucleus and a chambered centriolar adjunct (a newly introduced character). This organization provides further support for these characters as potential synapomorphies for the RTA clade. By the end of the spermiogenesis, the nucleus and axoneme coils within the cell and a multi-layered secretion sheath are formed representing cleistospermia. The function of the thick secretion sheath is still unknown, but might be correlated either with the residency time in the female (insemination until oviposition) since female S. malitiosa do not lay eggs before the fourth month after copulation or with the receptivity-inhibiting substances suggested for this species.     

Spermiogenesis in Psilochorus simoni (Berland, 1911) (Pholcidae, Araneae): evidence for considerable within-family variation in sperm structure and development

A large number of characters and considerable variation among taxa make animal sperm cells promising objects for phylogenetic studies. However, our knowledge about sperm structure and development in spiders is still rudimentary. In pholcids, previous studies of two species representing different subfamily level taxa have revealed conspicuous differences. Here, we report on a representative of a third subfamily level taxon, confirming substantial variation in sperm structure and development within the family. The male genital system in Psilochorus simoni (Berland, 1911) consists of paired testes and deferent ducts which lead into a common ejaculatory duct. The somatic cells of the testes show a high secretory activity, and produce at least two different kinds of secretion. The spermatozoa show features already known from other Pholcidae as well as unique characters. The acrosomal vacuole is tube-like with a narrow subacrosomal space. The axoneme migrates deep into the nucleus and is finally located near the acrosomal vacuole. Thus, the postcentriolar elongation of the nucleus is very long. A centriolar adjunct is not present and after the coiling process the implantation fossa is completely filled with glycogen which is also found in larger amounts within the cytoplasm of the sperm cell. After the coiling process, a vesicular area is present that becomes most prominent in the periphery of the sperm cell and surrounds the axoneme and parts of the nucleus. The secretion sheath surrounding the mature spermatozoon is already formed in the lumen of the testis, possibly by a secretion present in the testis but absent in the deferent duct. Sperm are transferred as cleistospermia. Results are compared with previous studies on pholcid spermiogenesis and sperm structure.     

Sperm storage and spermatozoa interaction with epithelial cells in oviduct of Chinese soft‐shelled turtle,Pelodiscus sinensis

Spermatozoa are known to be stored within the female genital tract after mating in various species to optimize timing of reproductive events such as copulation, fertilization, and ovulation. The mechanism supporting long‐term sperm storage is still unclear in turtles. The aim of this study was to investigate the interaction between the spermatozoa and oviduct in Chinese soft‐shelled turtle by light and electron microscopy to reveal the potential cytological mechanism of long‐term sperm storage. Spermatozoa were stored in isthmus, uterine, and vagina of the oviduct throughout the year, indicating long‐term sperm storage in vivo. Sperm heads were always embedded among the cilia and even intercalated into the apical hollowness of the ciliated cells in the oviduct mucosal epithelium. The stored spermatozoa could also gather in the gland conduit. There was no lysosome distribution around the hollowness of the ciliated cell, suggesting that the ciliated cells of the oviduct can support the spermatozoa instead of phagocytosing them in the oviduct. Immune cells were sparse in the epithelium and lamina propria of oviduct, although few were found inside the blood vessel of mucosa, which may be an indication of immune tolerance during sperm storage in the oviduct of the soft‐shelled turtle. These characteristics developed in the turtle benefited spermatozoa survival for a long time as extraneous cells in the oviduct of this species. These findings would help to improve the understanding of reproductive regularity and develop strategies of species conservation in the turtle. The Chinese soft‐shelled turtle may be a potential model for uncovering the mechanism behind the sperm storage phenomenon.     

Male genital system and spermiogenesis of Nanorchestes amphibius (Acari: Endeostigmata: Nanorchestidae): anatomy,histology, and evolutionary implications

In the present article the anatomy and histology of the male genital system of an endeostigmatid mite are described for the first time. The Endeostigmata probably are a paraphyletic group supposed to include the most primitive actinotrichid mites. In Nanorchestes amphibius, the testis comprises a paired germinal region connected with an unpaired glandular region. In the germinal region, spermiogenesis takes place in cysts of a somatic cell containing germ cells representing the same developmental stage. In the lumen of the glandular region, the spermatozoa are stored together with secretions of the glandular epithelium. These secretions are probably involved in the formation of spermatophores. From the glandular region, spermatozoa and secretions are released into the vasa deferentia that histologically can be divided into three sections, beginning with a short paired region with strong circular muscles serving as a sphincter, continuing with a paired proximal zone, followed by a short unpaired distal section. The distal vas deferens leads into the chitinous, unpaired ductus ejaculatorius which is followed by the progenital chamber. The ductus ejaculatorius is composed of a proximal section and a proximal, central, and anterior chamber. It is accompanied by a complex system of muscles and sclerites probably involved in the formation and ejaculation of the spermatophore. A similar organization can also be found in Prostigmata, but not in Oribatida. Anterior to the progenital chamber is located a paired accessory gland that probably produces a lipid secretion. Spermiogenesis is characterized by disintegration of the nuclear envelope, condensation of chromatin, and extensive reduction of the amount of sperm cell cytoplasm. The mature aflagellate, U-shaped spermatozoa are simple in structure and lack mitochondria and an acrosome complex. The results do not support the current view that Nanorchestidae are more closely related to Sarcoptiformes, i.e., Oribatida and Astigmata, than to Prostigmata.     

Morphology and histology of male and female reproductive systems in the inseminating species Scoloplax distolothrix (Ostariophysi: Siluriformes: Scoloplacidae)

The morphology and histology of male and female reproductive systems were examined in Scoloplax distolothrix. Internal insemination was documented in this species by the presence of sperm within the ovaries. Mature males and females have elongated genital papillae, exhibiting a tubular shape in males and a plain heart‐shape with two median protuberances in females. The testes are two elongated structures that converge ventrally, under the intestine, towards the genital papilla. They are joined at the caudal end, forming an ovoid single chamber for sperm storage. Secretory regions were not observed. In the lumen of the testicular tubules, spermatozoa can be tightly packed along their lengths, but do not constitute a spermatozeugmata. The lumen of the sperm storage chamber and spermatic duct are filled with free spermatozoa without the accompanying secretions. The ovaries are bird‐wing shaped, saccular structures that converge ventrally under the intestine, towards the genital papilla. They are joined at the caudal end, forming a tubular chamber possibly destined for oocyte storage. An oviduct with an irregular outline connects the chamber to the tubular region of the genital papilla. No distinct sperm storage structure was found in the ovaries. The unique male and female genital papillae suggest that these structures are associated with the reproductive mode in scoloplacids, representing evidence for insemination. The occurrence of free spermatozoa, without the accompanying secretions and not arranged in a spermatozeugmata can be associated with the presence of a tubular male genital papilla for sperm transfer to the female genital tract. This reinforces the idea that sperm packets are not necessary for all inseminating species. The male reproductive system in scoloplacids is very different from that in auchenipterids, a second catfish family with insemination, which indicates that the occurrence of insemination is not connected to the internal morphology of reproductive organs. J. Morphol., 2008. © 2008 Wiley‐Liss, Inc.     

Sperm release behaviour and fertilization in the grass goby

Nesting males of the grass goby Zosterisessor ophiocephalus showed bouts, with intervals of c. 30 min duration, of upside-down movements while rubbing its genital papilla onto the ceiling of its burrow. Such behaviour was shown during female courting and spawning, and even after female removal. Observations showed that this behaviour was associated with the release of a sperm trail on the substratum and clumped spermatozoa in water, agglutinated with a mercury-bromophenol blue and PAS positive glycoprotein secretion of the sperm duct glands. Agglutination in the secretion delayed the activation of spermatozoa and contributed a steady supply, for up to 40 min, of motile spermatozoa during prolonged egg laying by the female. Sperm released before egg laying achieved c. 50% fertilization success compared with nearly 100% obtained if the sperm was released during egg laying. The sperm release behaviour may improve the nest owner's reproductive success against intruders or sneakers. It also allows defence of the nest while the female is spawning and may allow the male to court other females in the proximity.     

Membrane specializations in the spermatozoa of collembolan insects

Here we describe the membrane specializations displayed by "dormant" collembolan spermatozoa, during the period when they are temporarily stored in the male genital ducts before being laid in the soil as a spermatophore, which is then picked up by the female. In the male deferent ducts and in the spermatophore, these "dormant" spermatozoa are rolled up into flattened ellipsoids that surround a central extracellular cavity filled with dense material. In this condition, the plasma membranes that surround the central extracellular cavity contain two types of membrane specializations. One consists of parallel rows of intramembrane particles on the E-face of the membrane facing the outside of the spermatozoa. The other consists of small orthogonal plaques of intramembrane particles intermingled with these rows. These plaques associate with the P-face of the membrane, and are therefore likely to represent preferential sites for receiving and transmuting environmental signals, especially whatever signal(s) induce these spermatozoa to transform into filiform and motile cells upon reaching the female spermatheca.     

Histochemical analysis of sperm storage in Helicolenus dactylopterus dactylopterus (Teleostei: Scorpaenidae).

The bluemouth rockfish, Helicolenus dactylopterus dactylopterus (De la Roche, 1809), is a zygoparous species with internal fertilization. The male urogenital papilla acts as the copulating organ, and the females retain the spermatozoa in their ovaries for up to 10 months. The objective of this study is to extend our knowledge of the mechanisms that allow the sperm to be retained in the ovaries for prolonged periods. To this end, we analyze the histochemical properties of: 1) the epithelium of the testicular sperm duct, 2) the sperm of the males, 3) the internal epithelium of the ovary wall, 4) the ovarian fluid, and 5) the spermatozoa storage crypts of females. The PAS (Periodic acid-Schiff) and bright Coomassie blue positive reactions of the epithelium of the spermatic duct point to the secretion of polysaccharides and proteins that could promote the bundling of the spermatozoa. The internal epithelium of the ovarian wall secretes polysaccharides, protein, and lipid compounds throughout the storage and spawning period. The acid nature of the ovarian fluid during the storage period may maintain the bundling of spermatozoa when they enter the ovary and may also inhibit sperm motility until the moment of fertilization. The polysaccharide granules that come from the cryptal epithelium into the cavity where spermatozoa are maintained may supply them with nutrients for the storage period. The presence of glucosaminoglycans on the surface of the sperm is probably related to the inhibition of spermatic motility produced by the acidic environment. They are absent in the spermatozoa located in the testicular ducts, relatively scarce in those of the duct of the copulating organ, and abundant in those within the intraovarian cryptal structures.     

Distribution of soltriol [1,25(OH)2-vitamin D3] binding sites in male sex organs of the mouse: an autoradiographic study

After injection of [3H]-1,25(OH)2-vitamin D3 (soltriol), nuclear labeling is found in Sertoli cells of testes, being highest at the stage of spermiosis, in epithelium of efferent ductules and caput epididymidis and in connective tissue cells of epididymis, in lamina propria and muscular sheath of deferent duct, and in epithelium and muscular sheath of dorsal and ventral prostate of the mouse. This labeling pattern is characteristic for [3H]-soltriol and differs from that for [3H]-dihydrotestosterone and [3H]-estradiol, although with overlap. The nuclear labeling with [3H]-soltriol suggests an action of the hormone on certain processes during spermatogenesis, on sperm maturation, on epididymal fluid resorption, and on secretion and transport of spermatozoa.