Ultrastructure of the reproductive system of the black swamp snake (Seminatrix pygaea). IV. Occurrence of an ampulla ductus deferentis

Seasonal morphological variation of the vas deferens of scorpion mud turtle (Kinosternon scorpioides)

This study aimed to characterize the morphology of the vas deferens ofKinosteron scorpioides by macroscopic and microscopic analysis. Were used 20 adult male jurarás collected at regular intervals during the year and divided into four experimental groups in the rainy and dry seasons, being processed for light microscopy, scanning electron microscopy and transmission electron microscopy. Morphometry for tubular and luminal diameters and epithelial height were also performed. On rainy season, vas deferens presented pseudostratified epithelium with cylindrical cells, spermatozoids and milky fluid in the lumen, with cytoplasmic organelles and lipid vesicles. On dry season, epithelium was pseudostratified with cuboid cells, with cellular debris and no spermatozoids. There was significant variation (p<0,05) for morphometry of vas deferens, with lower values of tubular and luminal diameters on rainy season, and higher epithelial height on dry season.

Observations on variation in the ultrastructure of the proximal testicular ducts of the Ground Skink, Scincella lateralis (Reptilia: Squamata)

The North American Ground Skink, Scincella lateralis, is a member of the most speciose family of lizards, the Scincidae. The only descriptions of the testicular ducts of skinks concern the light microscopy of 13 species in eight other genera. We combine histological observations with results from transmission electron microscopy on a sample of skinks collected throughout the active season. The single rete testis has squamous epithelium with a large, indented nucleus and no junctional complexes between cells or conspicuous organelles. Nuclei of sperm in the rete testis area are associated with cytoplasmic bodies that are lost in the ductuli efferentes. The ductuli efferentes have both ciliated and nonciliated cells and show little seasonal variation except for the narrowing of intercellular canaliculi when sperm are absent. When the ductus epididymis contains sperm, the anterior one-third lacks copious secretory material around luminal sperm, whereas in the posterior two-thirds sperm are embedded in a dense matrix of secretory material. Light and dark principal cells exist and both contain saccular, often distended rough endoplasmic reticula, and widened intercellular canaliculi that bridge intracellular spaces. Junctional complexes are lacking between principal cells except for apical tight junctions. Electron-dense secretory granules coalesce at the luminal border for apocrine release. The cranial end of the ductus deferens is similar in cytology to the posterior ductus epididymis. Each of the nine squamates in which the proximal testicular ducts have been studied with electron microscopy has some unique characters, but no synapomorphies for squamates as a group are recognized.

Peptidase activities in Crotalus durissus terrificus semen

To understand the role of peptidases in seminal physiology ofCrotalus durissus terrificus, activity levels of representative enzymes in semen and their sensitivities to inhibitors, cofactors, and peptide hormones were evaluated. The existence of seminal fractions and the association of peptidases with these fractions were also characterized for the first time in snakes. The prominent inhibitors of aminopeptidases (APs) were amastatin for acid, basic, and neutral; bestatin for basic; and diprotin A for dipeptidyl-IV. Cystyl and prolyl-imino APs were similarly susceptible to the majority of these inhibitors. The basic and neutral were characterized as metallo-peptidases, acid AP was activated by MnCl2, and cystyl, prolyl-imino, and type I pyroglutamyl were characterized as sulphydryl-dependent APs. Angiotensin II, vasotocin, bradykinin, fertilization-promoting peptide, and TRH altered the majority of these peptidase activities; these peptides are possible substrates and/or modulators of these peptidases. Peptidase activities were found in all seminal fractions: seminal plasma (SP), prostasome-like (PR) structures, and soluble (S-) and membrane-bound fractions (MFs) of spermatozoa. The levels of activity of each peptidase varied among different seminal fractions. In SP, the higher activities were puromycin-insensitive neutral and basic APs. In PR, the higher activity was puromycin-insensitive neutral AP. In spermatozoa, the higher activity in subcellular SF was puromycin-sensitive neutral, while in MF both puromycin-sensitive and -insensitive neutral APs were equally higher than the other examined peptidases. Data suggested that these peptidases, mainly basic and neutral, have a high relevance in regulating seminal functions ofC. d. terrificus.

Ultrastructural evidence for secretion from the epithelium of ampulla ductus deferentis of the fan-throated lizardSitana ponticeriana Cuvier

Among reptiles, an ampulla ductus deferentis has been reported only in Squamata. Fairly detailed studies are available only for two species, the lizard Calotes versicolor (Fam: Agamidae) and the snake Seminatrix pygaea (Fam: Colubridae). The light microscopic study on C. versicolor revealed the ampulla to be a prominent organ, whereas the light and transmission electron microscopic study in S. pygaea revealed it to be discernable only in histological preparations. Further, the epithelium of the ductal portion of vas deferens as well as the ampulla of C. versicolor appears to contribute to the seminal plasma and can also phagocytose dead sperm, whereas in S. pygaea neither of these roles has been established. Thus, we hypothesize that there may be variations in the anatomy, histology, and the role of the vas deferens in general, and the ampulla in particular, of the squamate reptiles. In this study, the ductus deferens of the small fan-throated lizard Sitana ponticeriana (Fam: Agamidae) was subjected to light and transmission electron microscopic analysis. In this lizard the ampulla is more prominent than in C. versicolor. The epithelium of the ductal portion of vas deferens consists of principal cells (with features reflecting roles in endocytosis and phagocytosis of dead sperm), dark cells (which are absent in the epithelium of the ductal portion of vas deferens of snakes), and basal cells. The ampulla of S. ponticeriana is differentiated into storage and glandular portions. The epithelium of the storage portion is like that in the ductal portion of the vas deferens, whereas that of the glandular portion, consisting of dark and light principal cells and foamy cells, is tall and forms into smooth villous folds. All three cell types show evidence for a role in secretion, in all likelihood different from each other, for release into the lumen to contribute to seminal plasma. These cells do not provide evidence of a role in phagocytosis of dead sperm. It appears that within the Squamata, the ductal ampulla differs in structure as well as function. We suggest that the ductal ampulla of agamid lizards is a composite gland of the ampulla ductus deferentis and seminal vesicles of mammals.