Sperm storage in Spermathecae of the great lamper eel,Amphiuma tridactylum (Caudata: Amphiumidae)

The spermathecae of ten female Amphiuma tridactylum were examined by light and electron microscopy during the presumed mating and ovipository seasons (March–August) in Louisiana. Spermathecae were simple tubuloalveolar glands in the dorsal wall of the cloaca. Six of the ten specimens were vitellogenic, and all of these specimens contained sperm in their spermathecae and had secretory activity in the spermathecal epithelium. Two nonvitellogenic females also had sperm in their spermathecae and active epithelial cells, whereas the other nonvitellogenic females lacked stored sperm and secretory activity in the spermathecae. In specimens storing sperm from March–May, the sperm were normal in cytology, and secretory vacuoles were contained within the epithelium. In the August sample, however, evidence of sperm degradation was present, and secretory material had been released into the lumen by an apocrine process. We therefore hypothesize that the spermathecal secretions function in sperm degeneration. © 1996 Wiley-Liss, Inc.     

Sperm aggregations in the spermatheca of female desmognathine salamanders (Amphibia: Urodela: Plethodontidae)

The alignment of sperm in a cloacal sperm storage gland, the spermatheca, was studied in female desmognathine salamanders by scanning and transmission electron microscopy. Females representing nine species and collected in spring, late summer, and fall in the southern Appalachian Mountains contained abundant sperm in their spermathecae. The spermatheca is a compound tubuloalveolar gland connected by a single common tube to the middorsal wall of the cloaca. Sperm enter the common tube in small groups aligned in parallel along their axes, and continue in a straight course until encountering divisions of the common tube (neck tubules) or luminal borders of distal bulbs, which can act as barriers. Sperm may form tangles, in which small clusters retain their mutual alignment, at the branches of the neck tubules from the common tube, or in the lumen of the distal bulbs, where subsequent waves of sperm collide with sperm already present. The nuclei of some sperm from the initial group to encounter the walls of the distal bulbs appear to become embedded in secretory material on the luminal border or in the apical cytoplasm of the spermathecal epithelial cells. We propose that these sperm become trapped in the spermatheca and are ultimately degraded. J. Morphol. 238:143–155, 1998. © 1998 Wiley-Liss, Inc.     

Annual cycle of sperm storage in spermathecae of the red-spotted newt,Notophthalmus viridescens (Amphibia: Salamandridae)

Female sperm storage was studied in a population of Notophthalmus viridescens from South Carolina. Spermathecae initiate production of a glycoprotein secretory product in October. At this time ovarian follicles are immature (0.5–0.9 mm dia), and mating does not occur despite spermiation in males. Six of the 10 females collected in December had sperm in their spermathecae, indicating onset of mating. Unmated females collected in October and sacrificed in February and March possessed mature ovarian follicles (1.3–1.4 mm dia), and the spermathecae contained large secretory vacuoles 2–3 μm dia. Release of secretory product is concomitant with the appearance of sperm in the spermathecae. Thus mated females lack secretory vacuoles in the spermathecal epithelium, and additional synthesis of secretory product does not occur. All females collected in February and March have mated. Sperm are embedded in the spermathecal epithelium and are undergoing degradation in February. Degradation of sperm in the lumen and epithelium is evident in specimens examined from May and June. Atresia of ovarian follicles begins in April in captive specimens, and specimens captured from the bay in May are spent. A general postbreeding emigration from the pond occurs in summer. Fourteen females collected 7 March were injected with human chorionic gonadotropin (hCG) on 9 March and laid fertile eggs 10–18 March. Two of these females were sacrificed each month from April-September; all retained some sperm in their spermathecae, but further oviposition did not occur. Four females were kept 1 year after oviposition of fertile eggs, and oviposition again was induced with hCG; these eggs were infertile, and spermathecae lacked sperm. Spermathecae are inactive from June-September in captive and wild-caught specimens. Sperm may be stored effectively up to 6 months (December-May), and no evidence was found for retention of viable sperm from one breeding season to the next. © 1996 Wiley-Liss, Inc.     

Sperm storage and degradation in the spermathecae of the salamander Eurycea Cirrigera

Spermathecae are exocrine glands in the roof of the female cloaca that store sperm. Cytological and histochemical data indicate that the one type of secretion into the lumen is a glycoprotein. After a period of stasis in the summer, production of the secretion is initiated in the fall, coincident with an increase in ovarian follicular size. By the time of maximal follicular development and most intense mating activity in March and April, the spermathecal epithelium is filled with secretory granules. The secretory material is released into the lumen, enveloping the sperm. Many sperm remain in the spermathecae after oviposition, and most of these sperm are degraded in the spermathecal epithelium or pass through interruptions in the spermathecal walls caused by desquamation. Sperm in contact with the stromal environment are phagocytized by leukocytes. Some sperm, however, may survive in the lumen until at least the following fall. These sperm retain normal cytology, but whether or not they remain fertile and intact until a subsequent ovipository cycle is unknown.     

Sperm storage by spermatodoses in the spermatheca of Trioza alacris (Flor, 1861) hemiptera,psylloidea, triozidae: A structural and ultrastructural study

Female insects generally store sperm received during mating in specific organs of their reproductive tract, i.e., the spermathecae, which keep the sperm alive for a long time until fertilization occurs. We investigated spermatheca morphology and ultrastructure in the psylloidean insect Trioza alacris (Flor, 1861 ) in which spheroidal sperm packets that we refer to as ‘spermatodoses’ are found after mating. The ectoderm‐derived epithelium of the sac‐shaped spermatheca that has a proximal neck, consists of large secretory and flat cuticle‐forming cells. Secretory cells are characterized by a wide extracellular cavity, bordered by microvilli, in which electron‐dense secretion accumulates before discharge into the spermathecal lumen. The cuticle‐forming cells produce the cuticular intima of the organ and a peculiar specialized apical structure, through which secretion flows into the lumen. At mating, the male transfers bundles of sperm cells embedded in seminal fluid into the spermathecal neck. Sperm cells proceed towards the spermathecal sac lumen, where they are progressively compacted and surrounded with an envelope that also encloses secretions of both male and female origin. We describe the formation of these sperm containing structures and document the contribution of the female secretion to spermatodose or female‐determined spermatophore construction. We also discuss the choice of the term ‘spermatodose’ for T. alacris and suggest it be used to refer to sperm masses constructed in the female reproductive organs, at least when they involve the contribution of female secretion. © 2011 Wiley Periodicals, Inc.     

Spermathecae of Salamandrina terdigitata (Amphibia: Salamandridae): Patterns of sperm storage and degradation

The spermathecae of female Salamandrina terdigitata were observed using light and transmission electron microscopy during the fallspring period of sperm storage and secretory activity and during the summer stasis. When sperm are stored inside the spermathecae, the product synthesized by spermathecal epithelial cells is exported into the lumen, where it bathes the sperm. During sperm storage some spermatozoa undergo degradation by the spermathecal epithelium. This process, which includes sperm capture by the apical microvilli, formation of endocytic vacuoles and production of lysosomes, becomes prominent shortly after oviposition. In many instances, cells filled with vacuolized spermatozoa and/or residual bodies undergo desquamation from the spermathecal epithelium and enter the lumen together with residual sperm. Desquamated cells, together with residual sperm, are a common feature in the spermathecal lumina at the end of the egg-laying season. Concomitant to the activity of the spermathecal epithelium, macrophages move into the spermathecae from the stroma and contribute to the degradation of both the residual sperm and desquamated epithelial cells. As a result of this degradation activity, spermathecae observed during the short summer stasis appear devoid of secretory product and sperm. By late summer, however, the spermathecae already show early signs of an imminent resumption of biosynthetic activity. © 1995 Wiley-Liss, Inc.     

Sperm aggregations in female Agkistrodon piscivorus (Reptilia:Squamata): a histological and ultrastructural investigation

Upon copulation in female Agkistrodon piscivorus, sperm migrate up the oviduct to sperm storage tubules (SSTs) in the posterior infundibulum. The epithelium of the SSTs is composed of ciliated and secretory cells and differs ultrastructurally from that of the epithelium lining the lumen of the posterior infundibulum. Sperm pass through an area composed primarily of ciliated cells at the opening of each gland before aligning themselves in parallel arrays with their nuclei facing an area composed primarily of secretory cells at the base of the tubules. Sperm are also found embedded inter- and intracellularly in the SSTs. The secretory vacuoles in the SSTs become highly electron dense after the start of the fall mating season along with the synthesis of lipid droplets. Histochemical analysis reveals that the alteration in secretory material density is caused by the production of neutral carbohydrates. Some sperm remain in aggregates in the nonglandular section of the posterior uterus until the time of ovulation. However, ultrastructural evidence indicates these sperm degrade before ovulation. Therefore, sperm in posterior aggregates have no role in fertilization of ovulated ova. The data presented here support the hypothesis that infundibular sperm storage is the mode that snakes utilize to sequester viable sperm until ovulation.     

Sperm transfer and storage in the lizard,Anolis carolinensis

The relationship of the hemipenis to the cloaca in copula and sperm storage and transport in the female oviduct were studied in Anolis carolinensis using light and scanning electron microscopy. During copulation, the hemipenis does not penetrate beyond the cloaca, but the two apical openings of the bifurcate sulcus spermaticus appose the openings of the oviducts from the cloaca. Sperm enter the sperm storage tubules between 2 and 6 hr after insemination and small amounts of sperm reach the infundibulum 6 to 24 hr following mating. Sperm storage tubules are embedded in the wall of the utero-vaginal transition, and are formed by the folding and fusion of the oviducal epithelium. The importance of the hemipenile-cloacal relationship and the role of sperm storage in the life history of A. carolinensis are discussed.     

Oviductal sperm storage structure and their changes during the seasonal (dissociated) reproductive cycle in the soft-shelled turtle Lissemys punctata punctata

The oviduct of the Indian fresh water soft-shelled turtle Lissemys punctata punctata was examined throughout the year under light and scanning electron microscopes to determine the location, histomorphological characteristics, and function of sperm storage structure, as well as their changes at different phases of the seasonal reproductive cycle. Sperm storage structures in the form of tubules were observed in the wall of isthmus throughout the year. These tubules developed either by folding or fusion of the oviductal mucosal folds and were lined by both ciliated and nonciliated epithelial cells. The height and secretory activities of the epithelia were markedly high during the breeding phase (August to September) but low in the nonbreeding phase (October to June). A few short tubules lined by cuboidal epithelium appear in the wall of infundibulum only during the breeding phase. Following mating (May), inseminated sperm were stored within the tubules of isthmus up to the pre-ovulatory stage (August). Thereafter, sperm associated with PAS-positive materials secreted from the epithelium (referred to as a carrier matrix) moved forward to the infundibulum and were stored within the storage tubules of the infundibulum for a short time. Subsequently, sperm evacuated the storage tubules and entered the oviductal lumen to fertilize the subsequently ovulated eggs during or prior to ovulation. The isthmus-tubules become shorter and narrower in the regressive phase (October to November) and remained so until the early preparatory phase (April). Sperm release might have been stimulated by estrogen secreted from the ovarian follicles of pre-ovulatory turtles. Stored sperm not utilized for fertilization remained viable not less than six months in the present turtle species.     

Sperm storage in females of the smooth newt (Triturus v. vulgaris L.): II. Ultrastructure of the spermathecae after the breeding season

Sperm storage in cloacal spermathecae was studied in females of Triturus v. vulgaris from southern England killed at the end of the breeding season in June. This species mates and oviposits eggs in ponds from March to June. Included in the sample were 12 unmated females collected in terrestrial situations in March and mated in the laboratory. Some of these females oviposited viable eggs in the laboratory whereas others did not oviposit after mating. In addition, we examined five females with unknown mating histories that were collected from a breeding pond in June. We found that all of the specimens contained some stored sperm and were similar in spermathecal ultrastructure. The spermathecae exhibited characteristics of secretory epithelium at the end of a cycle, including irregular heterochromatic nuclei surrounded by scant cytoplasm, absence of organelles involved in synthetic activities, few secretory vacuoles, and wide intercellular canaliculi. Spermiophagy by the spermathecal epithelium was extensive. In contrast, spermathecae from females at the beginning of the breeding season as reported in our previous study were actively producing a PAS+ secretion and did not exhibit spermiophagy. Spermiophagy is a means of eliminating sperm prior to the next breeding season.     

Sperm storage in the spermatheca of the red-back salamander,Plethodon cinereus (Amphibia: Plethodontidae)

In northern Indiana, the mating season of Plethodon cinereus occurs after hibernation from March until June, when oviposition begins. During the mating season, a female stores sperm in its spermatheca, a compound tubular gland in the roof of the cloaca. The apical cytoplasm of the spermathecal epithelium is filled with large secretory vacuoles whose product is released while sperm are stored. Females induced to oviposit in June and July by injections of human chorionic gonadotropin (hCG) still retain much sperm 1 month after oviposition, but secretory vacuoles are absent in all specimens sacrificed in July and August. Instead, some sperm are embedded in the spermathecal epithelium with resultant spermiophagy involving lysosomes. A female sacrificed in September 2 months after oviposition possesses scant sperm, but spermiophagy alone does not seem extensive enough to account for the decrease in sperm numbers. Females sacrificed in October prior to hibernation lack sperm in their spermathecae; some secretory vacuoles are present, but they are not as numerous or as enlarged as in specimens collected in March and May. Inter- and intrafamilial differences in the cytology of sperm storage may not be phyletically informative at the family level but related to species-specific reproductive adaptations. J. Morphol. 234:131–146, 1997. © 1997 Wiley-Liss, Inc.     

The morphogenesis of spermathecae and spermathecal glands in Drosophila melanogaster

Sperm storage in female insects is important for reproductive success and sperm competition. In Drosophila melanogaster females, sperm viability during storage is dependent upon secretions produced by spermathecae and parovaria. Class III dermal glands are present in both structures. Spermathecal glands are initially comprised of a three-cell unit that is refined to a single secretory cell in the adult. It encapsulates an end-apparatus joining to a cuticular duct passing secretions to the spermathecal lumen. We have examined spermatheca morphogenesis using DIC and fluorescence microscopy. In agreement with a recent study, cell division ceases by 36 h after puparium formation (APF). Immunostaining of the plasma membrane at this stage demonstrates that gland cells wrap around the developing end-apparatus and each other. By 48–60 h APF, the secretory cell exhibits characteristic adult morphology of an enlarged nucleus and extracellular reservoir. A novel finding is the presence of an extracellular reservoir in the basal support cell that is continuous with the secretory cell reservoir. Some indication of early spermathecal gland formation is evident in the division of enlarged cells lying adjacent to the spermathecal lumen at 18 h APF and in cellular processes that bind clusters of cells between 24 and 30 h APF.     

Ultrastructure of the reproductive system of the black swamp snake (Seminatrix pygaea): Part I. Evidence for oviducal sperm storage

Oviducal sperm storage in the viviparous (lecithotrophic) colubrid snake Seminatrix pygaea was studied by light and electron microscopy. Out of 17 adult snakes examined from May–October, sperm were found in the oviducts of only two specimens. In a preovulatory female sacrificed 14 May, sperm were found in the oviducal lumen and sperm storage tubules (SSTs) of the posterior infundibulum. In a nonvitellogenic female sacrificed 9 June, sperm were found in the lumen and glands of the posterior uterus and anterior vagina, indicating a recent mating. The glands in the posterior infundibulum and vagina were simple or compound tubular, whereas glands in the uterus always were simple tubular. The epithelium of the sperm storage glands was not modified from that lining the rest of the oviduct. The cuboidal or columnar epithelium consisted of alternating ciliated and secretory areas. The secretory product released into the lumen by a merocrine process contained mucoprotein. Lipid droplets also were numerous in the epithelium. Portions of sperm sometimes were embedded in the apical cytoplasm or in secretory material. A carrier matrix containing a mucoid substance, desquamated epithelium, lipids, membranous structures, and possibly phagocytes was found around sperm in the posterior uterus. J. Morphol. 241:1–18, 1999. © 1999 Wiley‐Liss, Inc.     

Spermathecal cytology of Ambystoma opacum (Amphibia: Ambystomatidae) and the phylogeny of sperm storage organs in female salamanders

Sperm storage glands, spermathecae, were examined from mated female Ambystoma opacum during the breeding season. No differences occur in the spermathecal ultrastructure of individuals sacrificed prior to oviposition and those sacrificed within 3 days of removal from tended clutches of recently oviposited eggs. The simple tubuloalveolar glands produce two types of secretory vacuoles. Apical secretory vacuoles contain glycosaminoglycans for export into the lumen to bathe stored sperm, perhaps providing the chemical/osmotic environment necessary for sperm quiescence. The other type of secretory vacuole contains an unsaturated lipid that is produced for export into the connective tissue surrounding the spermathecae. The role of this secretion may involve the contraction of myoepithelial cells, resulting in sperm expulsion. Some sperm undergo degradation in the spermathecal epithelium, and an interepithelial leukocyte was observed in one specimen. Apical secretory vacuoles and sperm are absent from the spermathecae of a specimen sacrificed 62 days after removal from a tended egg clutch. This is the first report on the spermathecal cytology of a salamander from the Ambystomatidae, and comparisons with salamanders from other families provide a morphological basis for considering spermathecae polyphyletic within the Caudata. © 1993 Wiley-Liss, Inc.     

Seasonal changes of sperm storage and correlative structures in male and female soft-shelled turtles, Trionyx sinensis

Reproductive ducts of male and female soft-shelled turtles, Trionyx sinensis were examined throughout the year (March, May, September, December) using brightfield and electron microscopes (TEM and SEM), to determine the location and histomorphological characteristics of sperm storage structures as well as their changes at different phases of the seasonal reproductive cycle. Sperm stored in the epididymis were also examined. In the male, spermatogenesis is initiated in spring (May), and then the mature sperm are released in autumn as an episodic event. Spermatogenesis is inactive in winter. However, in this species, the epididymis contains sperm throughout the entire year. Sperm observed in the epididymis are intact and some structures are uniquely different from other reptiles, and is characterized by 35–40 concentric mitochondria with a dense core in the centre. Many glycogen granules are observed in the cytoplasm of the midpiece. However, the epithelial cell type of epididymal duct change in different seasons. The cells are fully developed with a highly secretory activity in September. The materials secreted from the epithelium might have the function as nourishment for the stored sperm. Sperm storage structures in the form of tubules are observed in the wall of the isthmus of the oviduct in hibernating females but are absent in the groups of May and September. These tubules develop either by folding or fusion of the oviductal mucosal folds and are lined by both ciliated and secretory cells. These tubules might provide a microenvironment for the sperm to enable its long-term storage. After being separated 4 months (December–March) from the male, sperm are observed in the tubules of the isthmus of the oviduct. The unique character of the sperm combined with the special sperm storage structures enable the sperm to maintain fertility and activity during their storage.     

Post-mating effects in the grasshopper, Gomphocerus rufus L. mediated by the spermatheca

In the female grasshopper Gomphocerus rufus mating replaces copulatory readiness with immediate and long-lasting `secondary defense', during which further mating attempts are efficiently repelled. The behavioral change is caused by secretions from the male accessory glands' white secretory tubule 1 which is injected with the spermatophore material into the female's spermathecal duct. A bristle field of contact chemoreceptors at the entry of the spermathecal duct into the endbulb is assumed to be stimulated by the secretion. Ablation of the bristle field, interruption of the nervous pathway between the spermatheca and the ventral nervecord, or severance of the latter sustains sexual receptivity after mating. Both the secretion from white secretary tubule 1 and the spermatophore contained in the spermatheca of a mated female are digested by proteolytic enzymes from spermathecal gland cells. Dissolved material is resorbed by similar glandular-like cells. The intersexual conflicts of interest and their evolutionary consequences are discussed. Accepted: 4 December 1998     

Sperm storage in the oviduct of the tropical rock lizard,Psammophilus dorsalis

The female rock lizard, Psammophilus dorsalis (Agamidae), lays multiple clutches of eggs over a period of 6 months (June–December). The later clutches of eggs are presumably fertilized by sperm stored from earlier matings, since testes and epididymides are regressed after August. Sperm storage is seen in pockets of the anterior vaginal region of the oviduct. Sperm recovered from the uterovaginal region are intact and motile. Discrete granules resembling the secretory granules present in the vas deferens also occur along with sperm in the vaginal sperm storage structures. The PAS-positive granules and acid phosphatase form important components of the secretions present along with sperm in the vaginal sperm storage pockets. The epithelium of the vaginal sperm storage pockets is PAS-positive and contains lipid. Several enzymes, including hydroxysteroid dehydrogenases and hydrolases, are localized histochemically in the epithelium of the vaginal sperm storage pockets. A possible role is suggested for the secretions from the male reproductive tract during sperm storage in the oviduct, in which physiological “dormancy” of the sperm during their storage may be maintained by the metabolic “milieu” in the vaginal sperm storage pockets by a mechanism similar to that effecting dormancy of the epididymal sperm in the male. © 1995 Wiley-Liss, Inc.     

A histological and ultrastructural investigation of the female reproductive system of the water snake (Erythrolamprus miliaris): Oviductal cycle and sperm storage

We studied the structural and cellular organisation of the oviduct of Erythrolamprus miliaris including its morphological variation during the reproductive cycle using light microscopy, scanning electron microscopy and transmission electron microscopy. Four anatomically distinct regions compose the oviduct of E. miliaris including the anterior and posterior infundibulum, glandular uterus, non-glandular uterus and pouch. The cells of the oviductal epithelium secrete material by apocrine and merocrine processes, which vary between the anatomical regions and according to each phase of the reproductive cycle. The infundibular epithelium secretes electron dense vacuoles, which suggests the production of lipids, whereas the epithelial secretion of the glandular uterus, non-glandular uterus and pouch creates lucent and slightly electron dense vacuoles, indicating the production of glycoproteins. The timing of mating, vitellogenesis and sperm storage directly influences the morphofunctional alterations in the oviducts of E. miliaris. Sperm storage occurs only in the infundibular receptacles with increased production of the neutral carbohydrates in the presence of male gametes. Sperm storage happens in vitellogenic, non-vitellogenic and pregnant females of E. miliaris. Thus, females may be able to produce multiple clutches at different seasons of the year regardless of mating during autumn.     

The Cloaca and Spermatheca of the Female Smooth Newt, Triturus vulgaris L. (Amphibia: Urodela: Salamandridae)

The anatomy and histology of the cloaca and spermatheca of 13 female smooth newts ( Triturus vulgaris ) were studied by light microscopy. The cloaca consists of a short, anterior tube (which receives the oviducts), which opens into a larger, more posterior chamber. The spermatheca, which is the only gland in the cloaca, consists of a mass of exocrine, acinar tubules which empty individually and dorsolaterally into the posterior part of the cloacal tube and all but the most posterior part of the cloacal chamber. Stored sperm are most abundant in the spermathecal tubules during the peak of the breeding season (in May and June); during their period of storage, the sperm do not appear to make intimate contact with the epithelial cells lining the spermathecal tubules. Longterm storage of viable sperm from one breeding season to the next is probably absent in the smooth newt. Sperm storage by and multiple insemination of females both occur in this species and are necessary preconditions for competition between the sperm of different males for the fertilization of eggs. However, sperm competition has not been demonstrated in the smooth newt.     

Pathways and destination of some male gland secretions in female Locusta migratoria migratorioides (R&F) after insemination

The white secretions (WS) from the tubules of the male accessory glands (AG) of Locusta migratoria are composed of peptides and proteins. The WS are transferred during mating to the female's spermatheca. They have been followed to their destinations with immunological and radioactive marker techniques. In the spermatheca, peptides are split off from WS-protein complexes, permeate the spermathecal epithelium via glandular cells, enter the hemolymph and attach to other proteins in various target organs such as the dorsal fat body, the preterminal/terminal oocytes, and the follicular cells. In developing eggs, they concentrate at the posterior pole where sperm enters the egg, and in early embryogenesis they are found in the germ band. These results extend the functions of the spermatheca and the role of the male during the reproductive process.