Morphological Tools for Describing the Male External Genitalia of Sapajus apella.

Sapajus apella is a wild monkey of South America distributed across almost all of Brazil. This species adapts to domesticated life and reproduces easily. The present study describes the macro- and microscopic morphology of male genital organs (penis, penis bone, glans penis, prepuce, bulb of penis, and urethra) of Sapajus apella. Four male monkeys were used in this study. For macroscopic description, the genitals were dissected, examined and photographed. For microscopic analysis, samples were stained by HE and Tricom Masson and analyzed by scanning electron microscopy and light microscopy. The penis has a gutter shape with numerous spines on the free part of the penis and glans, and showed cavernous body elements in which mesenchymal cells appear. The glans penis is well developed with a broad crown shape. The prepuce does not cover the free part of the penis. The bulb displays well-developed muscle structure and the membranous urethra is very elongated. These results reveal that Sapajus apella shows specific male genital features, different from other primates.

The interleukin 1 (IL-1) system in the uteroplacental complex of a cartilaginous fish, the smoothhound shark, Mustelus canis.

Cartilaginous fish are the oldest extant jawed vertebrates and the oldest line to have placentae. Their pivotal evolutionary position makes them attractive models to investigate the mechanisms involved in the maternal-fetal interaction. This study describes the tissue expression of the cytokine interleukin-1 (IL-1) alpha, IL-1 beta and its specific membrane receptor, IL-1 receptor type I (IL-1R tI) in a placental cartilaginous fish, the smoothhound shark, Mustelus canis. The presence of this cytokine has been reported in many mammalian placentae, as well as in the placenta of a squamate reptile and this study extends these observations to the cartilaginous fishes. The uteroplacental complex in M. canis consists of a yolk sac modified into a functional yolk sac placenta and complimentary uterine attachment sites. Immunohistochemistry for IL-1 alpha, IL-1 beta and the receptor reveals leucocytes of both the mother and fetus to be positive, as well as the apical aspect of paraplacental cells and the apical vesicles in the umbilical cord epithelium. Yolk sac endoderm is also positive with all the stains while the ectoderm is positive only for IL-1 alpha. Immunoreactivity in the uterine epithelium was obtained for IL-1 alpha and the receptor. The egg envelope is always negative. In light of the recent finding of IL-1 beta gene in a cartilaginous fish and of the high level of conservation of proteins implicated in IL-1 action, our data suggest that IL-1 system is a key mediator of the materno-fetal interaction since the oldest extant placental vertebrates.

Ultrastructure of the reproductive system of the black swamp snake (Seminatrix pygaea). III. Sexual segment of the male kidney.

In mature male snakes and lizards, a distal portion of the nephron is hypertrophied in relation to its appearance in females and immature males. This sexual segment of the male kidney apparently provides seminal fluid that is mixed with sperm and released into the female cloaca during copulation. In this article, we provide the first study at the ultrastructural level of seasonal variation in the sexual segment of the kidney of a squamate, the natricine snake Seminatrix pygaea. Previous workers have indicated that the sexual segment is secretory only when the testes are spermatogenically active. The sexual segment of the kidney in S. pygaea does not go through an extended period of inactivity but does show a cycle of synthesis and secretion that can be related to the spermatogenic cycle and mating activity. We show that synthesis of secretory product is initiated with the onset of spermatogenic activity in the spring and culminates with completion of spermiation in the fall. Secretion of the product, however, occurs in a premating period in March when the testes are inactive. Secretion during this premating period is probably necessary to provide time for the passage of the products down the ureter in order to mix with sperm during mating later in spring.

Gestational morphogenesis of the uterine epithelium of the gummy shark (Mustelus antarcticus).

Developing embryos of the non-placental, viviparous gummy shark (Mustelus antarcticus) are supplied with yolk from external and internal yolk sacs throughout the initial stages of gestation. Yolk supplies are exhausted by the 7th month of an 11-12 month gestation. During embryonic development, there is an approximate 800% gain in dry mass. These factors suggest nutrients are transferred from the mother to the young. The results of the present study provide some insights into how this is occurring. The uteri are paired and both are functional. Using both light and transmission electron microscopy, regions of the uterus were examined throughout maturation and gestation. The layers of the uterine wall throughout the entire length are similar to the uteri of other chondrichthyans previously examined. The uterine epithelium of the body of the uterus is smooth contoured, does not form villi, and undergoes cyclical and secretory changes throughout maturity and gestation. In immature uteri, the epithelium is simple columnar with minimal periodic acid-Schiff-positive and Alcian blue-positive secretory vesicles. In mature uteri, the epithelium is highly stratified with cuboidal cells containing numerous Alcian blue-positive and periodic acid-Schiff-positive vesicles. With pregnancy, prominent changes include a reduction in the number of cell layers, a reduction in cell size, a reduction in the connective tissue intervening between epithelium and blood vessel endothelium, and an increase in blood vessel number and size, so that at term, the uterine compartment consists of a single layer of squamous cells immediately underlain by sinusoidal-like blood vessels. These features along with a small number of secretory vesicles, dilated intercellular spaces, and clear transport vesicles suggest the transepithelial transfer of water and minerals from the maternal to embryonic environment, supplemented by minimal uterine secretions. This is defined as minimal histotrophy and this article represents the first detailed description of this reproductive mode.

Microscopic organization of the sperm storage tubules in the oviducal gland of the female gummy shark (Mustelus antarcticus), with observations on sperm distribution and storage.

Oviducal gland morphology, the microscopic organization of the terminal zone, and sperm storage were described in the female gummy shark (Mustelus antarcticus). Mustelus antarcticus is a nonplacental viviparous hound shark, which displays minimal histotrophy during embryonic development. The animals examined represented all stages of maturity and gestation. The oviducal gland was found to have the same fundamental zonation as in most chondrichthyans. Using recent terminology, the oviducal gland of chondrichthyans has an anterior club zone, followed by a papillary zone, both of which produce jelly that surrounds the egg, a baffle zone that elaborates the tertiary egg envelope and a terminal zone, where sperm storage occurs. Each zone is composed of simple tubular glands that connect to transverse grooves, which extend the full width of the gland. The exception is the terminal zone, which does not have transverse grooves but consists of individual tubules. The microscopic organization and histochemical nature of the zones display similar patterns to those of other chondrichthyan genera. Tubules of the terminal zone contain four types of cell: ciliated cells, alcian blue-positive secretory cells, periodic acid-Schiff and alcian blue-negative secretory cells, and secretory columnar cells. These tubules end in recesses, the sperm storage tubules, which extend beyond the periphery of the baffle zone. Sperm were stored in the sperm storage tubules of all maturing and mature animals examined. Of note is the observation of stored sperm in an animal 1 year prior to first ovulation. Sperm were also observed throughout the uterine sphincter, body of the uterus, isthmus, and oviduct of maturing and mature animals, and in the uterine sphincter of an immature animal. These sperm represent immediately postcopulation aggregations of sperm and sperm in the process of migrating to the site of storage or to the site of fertilization.

Ultrastructure of the male genital ducts of the clearnose skate Raja eglanteria.

Tissues from the male genital ducts of six specimens of the clearnose skate Raja eglanteria, comprising the Leydig gland, upper and lower epididymis, ductus deferens and seminal vesicle, were fixed and embedded for ultrastructural examination. In the Leydig gland, two types of columnar cells were identified, one bearing microvilli, a basal nucleus and evidence of active secretion with plentiful endoplasmic reticulum and numerous secretory droplets, and the other pyriform with cilia, and swathes of cytofilaments emanating from prominent desmosomes. Occasional crystalloid intramitochondrial inclusions were seen in the first type, with a periodicity of 24 nm. The upper epididymis was composed of cuboidal cells with microvilli and cilia and irregular electron dense granules, some of which were basally situated and extremely large, often within cells resembling intraepithelial leucocytes; such cells were also seen in the stroma underlying the epithelium. The lower epididymis cells also bore microvilli and cilia and were heavily vacuolated with fatty inclusions as well as the granule-laden leucocytes seen previously. In the ductus deferens, cells had masses of long cilia with occasional microvilli; endoplasmic reticulum was well developed, forming complex arrays with sparse secretory droplets and basal mitochondria. In the seminal vesicle there were two cell types, the most common having long cilia and short microvilli and an occasional, paler cell with supranuclear accumulations of small, round mitochondria. These ultrastructural appearances have been related to cell glycosylation and functions including protein secretion, water absorption and waste removal, and illustrate how structure and function vary down the length of the genital tract.

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.

Female sperm storage in reptiles.

Internal fertilization and oviparity most likely are symplesiomorphies for modern reptiles, and viviparity has evolved independently numerous times in Sauria and Serpentes. Oviducal sperm storage is known in females of all taxa except Amphisbaenia. However, in Rhynchocephalia and Crocodilia, sperm storage is poorly studied, and specialized sperm storage tubules (Ssts) are unknown. We use the molecular phylogenetic hypothesis [(Chelonia+Archosauria) (Squamata)] to trace evolution of sperm storage characters. Ssts arose independently in Chelonia and Squamata. Turtles possess albumen-secreting glands in the anterior half of the oviduct (the tuba or isthmus), and the most distal of these glands also serve as Ssts; in addition, some turtles possess Ssts in the adjacent segment of the oviduct, the uterus. Squamates lack albumen-secreting glands, and the ancestral state is possession of Ssts in the posterior infundibulum (uterine tube). Secondarily, iguanids have evolved vaginal Ssts. In this paper, we present the first ultrastructural observations on vaginal Ssts in lizards, using Anolis sagrei (Polychrotidae). Proximally, the neck of these simple tubular glands continues the alternation of ciliated and secretory cells lining the lumen of the vagina. However, the epithelial cells of the distal sperm storage area are neither secretory nor ciliated. The Ssts of Anolis are more similar to those of birds more than to infundibular receptacles in snakes and lizards.

Glycosylation of the male genital ducts and spermatozeugmata formation in the clearnose skate Raja eglanteria.

Genital ducts of three male Raja eglanteria were fixed and embedded in epoxy and methacrylate resin. Epoxy resin sections from the Leydig gland, upper and lower epididymis, ductus deferens and seminal vesicle were stained with 20 labelled lectins to examine their glycosylation. The Leydig gland consisted of columnar epithelial cells expressing N-linked glycans, N-acetyl galactosamine, glucosamine and lactosamine residues and sialic acid. Interspersed were ciliated cells of a different glycotype. The upper epididymis of cuboidal epithelium had a strongly glycosylated, ciliated apical surface and cytoplasmic granules that stained heavily with many lectins, with increased glycosylation compared to the Leydig gland. In the lower epididymis, tall, vacuolated cells showed some differences and a slight reduction in lectin staining. The ductus deferens contained two cell types and showed increased terminal N-acetyl galactosamine. The ciliated cuboidal epithelium of the seminal vesicle had marked differences from the ductus epithelium, with decreased N-acetyl galactosamine and lactosamine expression but increased subterminal N-acetyl lactosamine and galactosamine expression and sialylation. Spermatozoa were suspended in a glycosylated matrix and, in the seminal vesicle, were embedded in solid masses of matrix forming spermatozeugmata. These data show changes in glycan expression along the male genital tract, probably related to the nurture and maturation of the spermatozoa as they travel towards the seminal vesicle.

Ultrastructure of sperm storage and male genital ducts in a male holocephalan, the elephant fish, Callorhynchus milii.

In chondrichthyes, the process of spermatogenesis produces a spermatocyst composed of Sertoli cells and their cohort of associated spermatozoa linearly arrayed and embedded in the apical end of the Sertoli cell. The extratesticular ducts consist of paired epididymis, ductus deferens, isthmus, and seminal vesicles. In transit through the ducts, spermatozoa undergo modification by secretions of the extratesticular ducts and associated glands, i.e., Leydig gland. In mature animals, the anterior portion of the mesonephros is specialized as the Leydig gland that connects to both the epididymis and ductus deferens and elaborates seminal fluid and matrix that contribute to the spermatophore or spermatozeugmata, depending on the species. Leydig gland epithelium is simple columnar with secretory and ciliated cells. Secretory cells have periodic acid-Schiff positive (PAS+) apical secretory granules. In the holocephalan elephant fish, Callorhynchus milii, sperm and Sertoli cell fragments enter the first major extratesticular duct, the epididymis. In the epididymis, spermatozoa are initially present as individual sperm but soon begin to laterally associate so that they are aligned head-to-head. The epididymis is a highly convoluted tubule with a small bore lumen and an epithelium consisting of scant ciliated and relatively more secretory cells. Secretory activity of both the Leydig gland and epididymis contribute to the nascent spermatophores, which begin as gel-like aggregations of secretory product in which sperm are embedded. Fully formed spermatophores occur in the ductus. The simple columnar epithelium has both ciliated and secretory cells. The spermatophore is regionalized into a PAS+ and Alcian-blue-positive (AB+) cortex and a distinctively PAS+, and less AB+ medulla. Laterally aligned sperm occupy the medulla and are surrounded by a clear zone separate from the spermatophore matrix. Grossly, the seminal vesicles are characterized by spiral partitions of the epithelium that project into the lumen, much like a spiral staircase. Each partition is staggered with respect to adjacent partitions while the aperture is eccentric. The generally nonsecretory epithelium of the seminal vesicle is simple columnar with both microvillar and ciliated cells.

Uterine epithelial-sperm interaction, endometrial cycle and sperm storage in the terminal zone of the oviducal gland in the placental smoothhound, Mustelus canis.

The fate of spermatozoa deposited within the female reproductive tract has been described in the smoothhound, Mustelus canis. Evidence of uterine epithelial-sperm interaction is presented, as well as documentation of sperm storage specifically in the terminal zone of the oviducal gland. Sperm fate is correlated with morphology of the endometrial cycle and specificity of storage in the oviducal gland. The endometrium of M. canis undergoes dramatic tissue remodeling associated with gestation. In females harboring fertilized ova or preimplantation yolk-reliant embryos, the uterine epithelium is simple cuboidal with mucous droplets for lubrication. The presence of the embryo elicits a response from the uterus, which becomes modified for nutrient and respiratory exchange into vascular uterine attachment sites that abut the distal aspect of the yolk sac. Areas of the uterus adjacent to the uterine attachment sites are termed paraplacental sites. Uterine attachment sites are simple squamous while the paraplacental epithelium is simple columnar. Paraplacental cells have basal metachromatic vesicles and a dense array of apical cytoplasmic filaments. Immediately postpartum the uterine attachment sites, now termed uterine or placental scars, begin to remodel to a mucous epithelium for the next gestational cycle. Paraplacental cells slough off the apical filamentous portion, and sperm become embedded in the epithelium. Bundled sperm occur throughout gestation in the terminal zone of the oviducal gland. Sperm are not embedded in the terminal zone epithelium as in the uterus. Following sperm release from the uterus, the paraplacental epithelium reverts to a mucous epithelium for the next reproductive cycle. Fertilization is presumed to occur in the anterior oviduct above the oviducal gland. The physiological mechanisms that mediate sperm-uterus attachment, release, and storage in the terminal zone of the oviducal gland are currently under investigation.