This study describes the male reproductive cycle of Sibynomorphus mikanii from southeastern Brazil considering macroscopic and microscopic variables. Sper- matogenesis occurs during spring-summer (September- December) and spermiogenesis or maturation occurs in summer (December-February). The length and width of the kidney, the tubular diameter, and the epithelium height of the sexual segment of the kidney (SSK) are larger in summer-autumn (December-May). Histochemi- cal reaction of the SSK (periodic acid-Schiff (PAS) and bro- mophenol blue (BB)) shows stronger results during summer-autumn, indicating an increase in the secretory activity of the granules. Testicular regression is observed in autumn and early winter (March-June) when a peak in the width of the ductus deferens occurs. The distal duc- tus deferens as well as the ampulla ductus deferentis ex- hibit secretory activities with positive reaction for PAS and BB. These results suggest that this secretion may nourish the spermatozoa while they are being stored in the ductus deferens. The increase in the Leydig cell nu- clear diameter in association with SSK hypertrophy and the presence of sperm in the female indicate that the mat- ing season occurs in autumn when testes begin to decrease their activity. The peak activity of Leydig cells and SSK exhibits an associated pattern with the mating season. However, spermatogenesis is dissociated of the copulation characterizing a complex reproductive cycle. At the individual level, S. mikanii males present a continu- ous cyclical reproductive pattern in the testes and kidneys (SSK), whereas at the populational level the reproductive pattern may be classified as seasonal semisynchronous. J.

http://www.ecoevo.com.br/publicacoes/alunos/claudio_rojas/2013_the_reproductive_cycle_male_sleep_snake%20%20%20%20%20%20%20Sibynomorphus%20mikanii%20(Schlegel,%20%20%20%20%20%201837)%20From%20%20Southeastern%20Brazil%20%20.pdf

The Reproductive Cycle of the Male Sleep Snake Sibynomorphus mikanii (Schlegel, 1837) From Southeastern Brazil

From seminiferous tubules of the testis, snakes and other squamates possess a system of efferent ducts, at least some of which function not only in the passage of sperm but also in sperm storage and as accessory sex glands. The seminiferous tubules connect to the rete testis, which passes sperm sequentially to the ductuli efferentes, the ductus epididymis, and the ductus deferens. The sexual segment of the kidney, described in chapter 11, is a male accessory sex gland that passes secretions into the ureter. The ductus deferens merges with its ipsilateral ureter in viperid snakes, whereas the ductus deferens empties posterior to its ipsilateral ureter and into its ipsilateral ampulla urogenital papilla in colubroid snakes. The above description represents a new interpretation of the alignment and termination of the urogenital ducts in viperid and colubroid snakes and will be illustrated and discussed in detail later in this chapter. Eventually, all products within the adjoined urogenital ducts exit via a single urogenital papilla or paired urogenital papillae into the cloaca. Depending on taxon, species may have ampullae ductus deferentia, ampullae ureters, and/or ampullae urogenital papillae. In this chapter, we review the literature on these structures, provide much new information, and indicate directions for future research. Male Urogenital Ducts and Cloacal Anatomy Stanley E. Trauthand David M. Sever

Male Urogenital Ducts and Cloacal Anatomy

Aspects of the reproductive biology of male and female Agkistrodon piscivorus are described using histological techniques, reviewed, and compared with historical data on A. piscivorus. These include anatomical description at the macro and microscopic levels, and correlation of the male and female urogenital cycles to the reproductive life history of A. piscivorus. New anatomical descriptions and discussion of the efferent ducts, including the ductuli efferentes, proximal and distal ductuli epididymides, ductus deferens, and ampulla ductus deferens, are also presented here at the light and electron microscopy levels. Morphology of all distinct regions of the male and female urogenital systems are discussed and compared with historical investigations on other squamates. In comparison to other snakes, A. piscivorus possesses some unique reproductive characters, whereas others are more conserved. In terms of the reproductive cycle, the ability of males and females to store sperm allows the dissociation of reproductive event timing between the sexes. Thus, the only event that must be coordinated between the sexes is copulation, which is proposed to occur in the fall and the spring in A. piscivorus. In females, the atrophy and activity of the reproductive organs (e.g., secretory activity) varies concurrently with vitellogenesis and the mating seasons. In males, spermatogenesis peaks in the summer, independent of the mating season, except in Louisiana where a spring and fall peak of spermatogenesis occur, and where the spring and fall mating seasons overlap. Renal sexual segment hypertrophy in males peaks in the fall and spring in more southern populations (Alabama and Louisiana) concurrent with fall and spring mating seasons. In Georgia, only a fall peak is observed. Secretory activity of the male excurrent ducts also peaks during times of mating activity in one population studied (Louisiana).

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Reproductive biology of agkistrodon piscivorus lacepede (squamata, serpentes, viperidae, crotalinae)

In this study, the anterior testicular ducts of the North American natricine snake Seminatrix pygaea are described using light and electron micros- copy. From the seminiferous tubules, the rete testis passes into the epididymal sheath, a structure along the medial border of the testis heavily invested with colla- gen fibers. The rete testis consists of simple, nonciliated cuboidal epithelium (principal cells). The intratesticular ducts of the rete testis are narrow (50-70 lm) at their junction with the seminiferous tubules, widen (80-100 lm) as they extend extratesticularly, and divide into smaller branches as they anastomose with the next tubules, the ductuli efferentes. The ductuli efferentes are lined by simple cuboidal epithelium but possess non- ciliated principal cells as well as ciliated cells. These are the only ducts in the male reproductive system with cili- ated cells. The ductuli efferentes are narrow (25-45 lm), divide into numerous branches, and are highly convo- luted. The ductus epididymis is the largest duct in diam- eter (240-330 lm), and the diameter widens and the epithelium thins posteriorly. The ductus epididymis is lined by nonciliated, columnar principal cells and basal cells. No regional differences in the ductus epididymis are apparent. Ultrastructural evidence suggests that all of the nonciliated principal cells in each of the anterior testicular ducts function in both absorption and secre- tion. Absorption occurs via small endocytic vesicles, some of which appear coated. Secretion is by a constitu- tive pathway in which small vesicles and a flocculent material are released via a merocrine process or through the formation of apocrine blebs. The secretory product is a glycoprotein. Overall, the characteristics of the ante- rior testicular ducts of this snake are concordant with those of other amniotes, and the traditional names used for snakes are changed to conform with those used for other sauropsids and mammals. J. Morphol. 271:104- 115, 2010. 2009 Wiley-Liss, Inc.

/pdf/ultrastructure-of-the-reproductive-system-of-the-black-swamp-4h7k8r73fw.pdf

Ultrastructure of the Reproductive System of the Black Swamp Snake (Seminatrix pygaea). VI. Anterior Testicular Ducts and Their Nomenclature

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

Light microscopy histology of efferent ductules and the ultrastructural organization of their epithelium were studied in the fan-throated lizard Sitana ponticeriana Cuvier. The ductules of this lizard are extra-testicular and arise from an extra-testicular rete testis. A major portion of the ductules is intra-epididymal and occupies the cephalic end of the epididymis. The ductules differentiate histologically into proximal and distal portions. The epithelium is formed of two major tall columnar cell types, the non-ciliated and ciliated, and one minor cell type, the basal cells. Dark cells were also identified. The non-ciliated cells possess microvilli towards the luminal end, tubular coated pits at the bases of the microvilli, coated vesicles in the apical cytoplasm and multivesicular bodies, lysosomes and mitochondria in the supranuclear and perinuclear cytoplasm, which reflects their role in the uptake of the material they are processing. These cells also participate in spermiophagy. The ciliated cells reflect their role in mixing the luminal content and/or its transport to the distal parts of the male tract. The lizard efferent ductules share many features in common with those of mammals and a crocodile and several other features with birds and a turtle. Spermiophagy by the efferent ductules is reported here for the first time in a reptile.

Efferent ductules of the fan-throated lizard Sitana ponticeriana Cuvier: light and transmission electron microscopy study

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. J. Morphol. © 2005 Wiley-Liss, Inc.

Ultrastructural evidence for secretion from the epithelium of ampulla ductus deferentis of the fan‐throated lizard Sitana ponticeriana Cuvier

The epididymis of the fan-throated lizard Sitana ponticeriana was examined with light and transmission electron microscopy to understand the cellular mechanisms of fabrication of secretion granules in epithelial principal cells, granule release into the lumen, and the fate of the dense structured granules after reaching the lumen. Principal cells of the ductus epididymis, except at the cauda, secrete electron-dense biphasic granules copiously, which decrease in abundance from the initial segment to corpus. The principal cell possesses a prominent Golgi apparatus and all versions of endoplasmic reticulum (ER), rough, smooth, and sparsely granulated. The material of the dense portion of the secretion granules, after processing at the Golgi apparatus, appears to accumulate in large ER cisternae in the supranuclear cytoplasm. It undergoes condensation when the cisternae become condensing vacuoles. Mitochondria appear to play a role in dense granule formation. The condensing vacuoles are displaced toward the apical cytoplasm when the material of the less dense portion is added to the condensing vacuoles at the Golgi area. Thus, the less dense and dense portions of the secretion granules are secreted and added to the condensing vacuoles separately. The composite granules are released into the lumen by exocytosis when the less dense portion merges with the luminal content, whereas the dense portion maintains its structured identity. The latter, initially measuring 1-2 microm in diameter, increases in size several times. It is inferred that these granules release their content gradually, resulting in the appearance of vacuoles, and suggesting that the granules have an insoluble matrix in which there is a sparingly soluble material. The substance leaching out of the granules appears to contribute to keeping the sperm quiescent and alive during storage in the male reproductive tract.

Light and electron microscopic observations of fabrication, release, and fate of biphasic secretion granules produced by epididymal epithelial principal cells of the fan-throated lizard Sitana ponticeriana cuvier.

The epididymis of the fan-throated lizard Sitana ponticeriana was subjected to light and transmission electron microscopic analysis to find the histological variation along the ductus epididymidis, describe the various cell types in the epithelium and compare the resulting descriptions with what is known for other reptiles and for amniotes. The ductus epididymidis of this lizard is differentiated along its length into four histologically distinct zones, initial segment, caput, corpus and cauda. The first three zones appear to be associated with secretion and absorption/endocytosis whereas the cauda appears to be concerned with absorption/endocytosis and storage. The epithelium consists of six different cell types, principal, narrow, apical, clear, basal and intraepithelial leucocytes as in the mammals. Principal cells, basal cells and intraepithelial leucocytes are present along the entire length. Narrow cells and apical cells are confined to the initial segment whereas clear cells occur in the cauda only. The principal cells from the initial segment to the corpus produce biphasic secretion granules measuring 1–2 µm in diameter. This paper reports on four histologically distinct zones along the length of the ductus epididymidis of the lizard S. ponticeriana and six different cell types in the lining epithelium.

Histological variation along and ultrastructural organization of the epithelium of the ductus epididymidis of the fan-throated lizard Sitana ponticeriana Cuvier

Veeramuthu Tamilarasan

Papers

Efferent ductules of the fan-throated lizard Sitana ponticeriana Cuvier: light and transmission electron microscopy study

Ultrastructural evidence for secretion from the epithelium of ampulla ductus deferentis of the fan‐throated lizard Sitana ponticeriana Cuvier

Light and electron microscopic observations of fabrication, release, and fate of biphasic secretion granules produced by epididymal epithelial principal cells of the fan-throated lizard Sitana ponticeriana cuvier.

Histological variation along and ultrastructural organization of the epithelium of the ductus epididymidis of the fan-throated lizard Sitana ponticeriana Cuvier