Development of the genital ducts in Telmatodrilinae (Tubificidae, Clitellata)

In Tubificidae, the male genital duct comprises a funnel in the testes segment, followed by a vas deferens, an atrium, and, frequently, a copulatory structure in the adjacent ovarian segment. There may also be a diffuse or compact prostate gland in association with the duct. The morphology and position of the genital ducts are important for the classification of the oligochaetous Clitellata. Different parts of the male duct, however, have been named without regard to whether they are homologous or not. One way to establish better hypotheses of homology is to study the detailed morphology and/or the development of the genital ducts. The morphogenesis of the genital ducts in Alexandrovia onegensis (Telmatodrilinae) is described. The male funnel originates by multiplication of peritoneal (mesodermal) cells in the posterior septum in the testes segment. A cord of these cells breaks through the septum and grows backwards into the next segment, where it connects to the epidermis. This cord gives rise to the vas deferens, and is therefore mesodermal in origin. The atrium in A. onegensis develops from a primary epidermal (ectodermal) invagination. The vas deferens and atrium connect and a continuous duct from the testes segment to the exterior is formed. Several compact prostate glands develop along the atrium, each being formed from cells in the atrial epithelium. The spermatheca develops from an invagination of the epidermis in the testes segment. The female duct is formed from peritoneal (mesodermal) cells in the posterior septum in the ovarian segment. These developmental findings strengthen the hypothesis about a closer relationship between the Telmatodrilinae and Tubificinae (both Tubificidae).     

Morphogenesis of the Genital Ducts and Spermathecae in Clitellio arenarius, Heterochaeta costata, Tubificoides benedii (Tubificidae) and Stylaria lacustris (Naididae) (Annelida, Oligochaeta)

The development of the male genital ducts in Clitellio arenarius, Tubificoides benedii, Heterochaeta costata (Tubificidae) and Stylaria lacustris (Naididae) is studied with the purpose of investigating the homologies between different parts of the ducts. In both Tubificidae and Naididae, the male duct comprises a funnel, a vas deferens and an atrium. There may also be a prostate gland (diffuse or compact) in association with the duct. The funnel and vas deferens, in all four species, originate from the peritoneal (mesodermal) cells in the posterior septa in the testes segment, whereas the atrium develops from an epidermal (ectodermal) invagination. The prostate glands have different origins in different taxa; in S. lacustris it differentiates from the peritoneal (mesodermal) cells surrounding the atrium, but in H. costata and T. benedii it develops by a multiplication of the atrial (ectodermal) cells; C. arenarius lacks a prostate gland. The development of the spermathecae and the female duct is also studied. The spermatheca is an epidermal invagination. The female duct is of mesodermal origin. However, the position of the duct differs; in S. lacustris the female duct is lateral and the pore is in the ovarian segment, while in the tubificids studied the duct is ventral with the pore in the segment behind the one containing the ovary.     

Two New Genera of Marine Tubificidae (Oligochaeta) from Australia's Great Barrier Reef

Macquaridriloides gen.n. is established for M. heronae from Heron Reef in Queensland, Australia. The species is characterized principally by its lack of spermathecae, and its elaborate male efferent ducts, each of which consists of (1) a ciliated vas deferens, (2) a ciliated and muscular atrium with diffuse prostates, and (3) a stout muscular, non-ciliar ejaculatory duct opening into a large copulatory sac surrounded by posterior prostates. The genus appears closely related to Macquaridrilus Jamieson, 1968, the habitat and zoogeography of which are briefly discussed. Heronidrilus gen.n. is established for H. fastigatus sp.n. and H. bihamis sp.n. both from Heron Reef. This genus is closely related to Macquaridriloides , but the two species differ from M. heronae in that they possess spermathecae and lack ejaculatory ducts.     

Development of the reproductive apparatus of the land planarian Rhynchodemus sylvaticus (Turbellaria: Tricladida) and its significance for classification in the genus

Seven specimens of Rhynchodemus sylvaticus (Leidy) collected from a variety of localities in the US and having variously developed copulatory organs are believed to represent stages in the development of the copulatory apparatus. Four specimens were juveniles with under-developed male components, one specimen had a well-developed female atrium and small male component, and two specimens were mature with a male organ twice the size of the female part. In early stages, the male component had sperm ducts, seminal vesicle, and narrow atrium; more mature stages had a considerable elongated atrium with thick folds in its muscularized wall, a massive muscular bulbus; and a sigmoid ejaculatory duct opening into the large bulbar cavity. Morphological features of mature male copulatory organs in all species of the genus Rhynchodemus are basically similar whereas external body features (color and number of dorsal stripes) of these same species differ.     

Histological and immunocytochemical study of deferens ducts in the Chinese rat snake (Zaocys dhumnades)

To investigate the relationship between structure and function of the deferens ducts in the Chinese rat snake (Zaocys dhumnades), morphological changes within an annual cycle were observed by routine histological techniques. Also, the correlation of androgen receptor (AR), estrogen receptor (ER), progesterone receptor (PR) and aromatase (Ar) expressions in the vas deferens and testis were studied immunohistochemically. To confirm that the sperm and the spherical structure existed in deferens ducts, we also used routine histological technique observed deferens ducts in the Striped-tailed rat-snake (Elaphe taeniura), Red-banded snake (Dinodon rufozonatum), and Tiger-spotted neck-troughed snake (Rhabdophis tigrina lateralis). The results showed that the deferens ducts of the Chinese Rat Snake were composed of efferent duct, epididymal duct and vas deferens. Efferent duct contained sperm from August-October, and the sperm were observed in the epididymal duct from August-the following January. Throughout the year (except July) a large number of sperm were present in the vas deferens where a previously unreported spherical structure formed by spermatids was observed, which showed no significant differences in the IOD values of AR-, ER-, PR- and Ar-immunoreactivities. Since the spermatids in the spherical structure were undergoing spermatogenesis and this phenomenon also existed in the Striped-tailed rat-snake and Red-banded snake, the term, seminiferous spherule, was named for this spherical structure This study demonstrated that the testis was the main site for snake spermiogenesis, and the seminiferous spherule in vas deferens was the other Both the epididymis and vas deferens stored sperm; however, the vas deferens was the main organ for sperm storage.     

Functional morphology of the copulatory system of box crabs with long second gonopods (Calappidae,Eubrachyura, Decapoda,Crustacea)

Male True Crabs use two pairs of gonopods to deliver mating products during copulation. Commonly, the second pair is shorter than the first pair, and most research to date has focused on species with short second gonopods. We investigated male and female copulatory organs in Calappula saussurei and Calappa pelii, two species of box crabs (Calappidae) with second gonopods which are longer than the first pair. Scanning electron microscopy and histological cross sectioning show that the female copulatory system is unique in several aspects: the genital duct is part concave and part simple type. The seminal receptacle is divided into two chambers, a ventral chamber of ectodermal and mesodermal origin, and a dorsal chamber of ectodermal origin. This dorsal chamber is the location of spermatophore reception during copulation. A sperm plug closes the dorsal chamber off. We propose that long second gonopods deliver male mating products directly into the dorsal chamber. To date, spermatophore reception has been associated with the mesodermal tissue of the seminal receptacle. The copulatory system of box crabs with long second gonopods shows novel deviations from this general pattern. J. Morphol. 276:77–89, 2015. © 2014 Wiley Periodicals, Inc.     

Genital system development of Williamia radiata (Gastropoda, Siphonariidae)

The adult anatomy and development of the genital system of the limpet Williamia radiata (Siphonariidae, Gastropoda) was investigated by means of 3D computer reconstruction and visualization of serial resin and paraplast light microscopical sections. As is characteristic for siphonariid species, the adult genital system consists of a single duct, the spermoviduct leading from the nidamental glandular system to the anteriorly located genital atrium with opening. The copulatory complex as well as the bursa copulatrix also open into the common genital atrium. The genital system develops from three separate anlagen. The posterior one appears first at a body length of 0.7 mm and gives rise to the ovotestis and part of the hermaphrodite duct. The nidamental glandular complex, the fertilization pouch-spermatheca complex, part of the hermaphrodite duct, the posterior part of the spermoviduct, and the bursa copulatrix develop later from the pallial anlage. Finally, the anterior anlage is formed on the right side of the head and gives rise to the genital atrium, the copulatory complex, and the anterior spermoviduct. This formation of the genital system from three, locally separated anlagen, differs strikingly from that of most other species of the Euthyneura. In both the Nudibranchia (Opisthobranchia) and the Stylommatophora (Pulmonata) development proceeds from a single site. We regarded this as a secondary condition as a result of derived features like heterochronies in development in these taxa. Comparison of development with that of other species of the Pulmonata allows conclusions on homology. The homology of the bursa copulatrix within the pulmonates is confirmed. The two separate chambers inside the spermoviduct of W. radiata correspond to oviduct and vas deferens of the freshwater Basommatophora.     

Segmental and cellular expression of aquaporins in the male excurrent duct

The male reproductive tract and accessory glands comprise a complex but interrelated system of tissues that are composed of many distinct cell types, all of which contribute to the ability of spermatozoa to carry out their ultimate function of fertilizing an oocyte. Spermatozoa undergo their final steps of maturation as they pass through the male excurrent duct, which includes efferent ducts, the epididymis and the vas deferens. The composition of the luminal environment in these organs is tightly regulated. Major fluid reabsorption occurs in efferent ducts and in the epididymis, and leads to a significant increase in sperm concentration. In the distal epididymis and vas deferens, fluid secretion controls the final fluidity of the luminal content. Therefore, the process of water movement in the excurrent duct is a crucial step for the establishment of male fertility. Aquaporins contribute to transepithelial water transport in many tissues, including the kidney, the brain, the eye and the respiratory tract. The present article reviews our current knowledge regarding the distribution and function of aquaporins in the male excurrent duct.     

Segmental and cellular expression of aquaporins in the male excurrent duct

The male reproductive tract and accessory glands comprise a complex but interrelated system of tissues that are composed of many distinct cell types, all of which contribute to the ability of spermatozoa to carry out their ultimate function of fertilizing an oocyte. Spermatozoa undergo their final steps of maturation as they pass through the male excurrent duct, which includes efferent ducts, the epididymis and the vas deferens. The composition of the luminal environment in these organs is tightly regulated. Major fluid reabsorption occurs in efferent ducts and in the epididymis, and leads to a significant increase in sperm concentration. In the distal epididymis and vas deferens, fluid secretion controls the final fluidity of the luminal content. Therefore, the process of water movement in the excurrent duct is a crucial step for the establishment of male fertility. Aquaporins contribute to transepithelial water transport in many tissues, including the kidney, the brain, the eye and the respiratory tract. The present article reviews our current knowledge regarding the distribution and function of aquaporins in the male excurrent duct.     

Co-expression and interaction of cubilin and megalin in the adult male rat reproductive system

Cubilin is a peripheral membrane protein that cooperates with the endocytic receptor megalin to mediate endocytosis of ligands in various polarized epithelia. Megalin is expressed in the male reproductive tract where it has been implicated in the process of sperm membrane remodeling. A potential role for cubilin in the male reproductive tract has not been explored. Using RT-PCR, we found that cubilin and megalin mRNAs are expressed in the efferent ducts, corpus and cauda epididymis, and proximal and distal vas deferens. Immunohistological analysis revealed that cubilin was expressed in nonciliated cells of the efferent ducts, principal cells of the corpus and cauda epididymis and vas deferens. Immunogold EM showed cubilin in endocytic pits, endocytic vesicles, and endosomes of these cells. The expression profile of cubilin in the male reproductive tract was coincident with that of megalin except in principal cells of the caput epididymis. Double immunogold labeling showed that cubilin and megalin co-localized within the endocytic apparatus and recycling vesicles of efferent duct cells. Neither protein was found in lysosomes. Injection of RAP, an antagonist of megalin interaction with cubilin, reduced the level of intracellular cubilin in cells of the efferent ducts and vas deferens. In conclusion, cubilin and megalin are co-expressed in cells of the epididymis and vas deferens and the endocytosis of cubilin in these tissues is dependent on megalin. Together, these findings highlight the potential for a joint endocytic role for cubilin and megalin in the male reproductive tract.     

The male reproductive system and mechanism of sperm transfer in Argulus japonicus (Crustacea: Branchiura)

The histomorphology of the male reproductive system and surface morphology of the “peg-and-socket” in Argulus japonicus are described from serial sagittal and transverse sections and scanning electron micrographs. The prostate complex consists of a glandular part, a reservoir for storing the secretion, and an efferent duct opening into the ejaculatory duct. The openings of both the vas deferens and the prostate duct into the ejaculatory duct are guarded by sphincters. The ejaculatory ducts, which are lined by tall columnar epithelial cells, do not open into the cuticle-lined genital atrium but are blind-ending tubes. This observation and results obtained from observing live specimens, as well as the fact that no spermatophores are formed, suggest that semen could leave the ejaculatory duct only after puncturing of its walls. It is suggested that sperm transfer is accomplished in the following manner: during copulation contraction of the muscular walls of the vas deferens and prostate duct causes semen to be pumped into the ejaculatory duct, which is then closed off by sphincters and a high internal pressure is developed. When a spermathecal spine penetrates the walls of the ejaculatory duct, semen flows from the ejaculatory duct into the spermathecal vesicle due to the higher pressure in the ejaculatory duct. This mechanism is analogous to the sucking up of fluid with a hypodermic syringe. © 1993 Wiley-Liss, Inc.     

Observations on the ultrastructure of the copulatory organ of Archilopsis unipunctata (Fabricius, 1826) (Proseriata,Monocelididae)

The copulatory organ in adult specimens of Archilopsis unipunctata has been studied by transmission electron microscopy.This copulatory organ is of the conjuncta-duplex type with eversible cirrus. The seminal vesicle, lined with a nucleate epithelium, is surrounded by spirally arranged muscles. The fibres are enclosed in a sheath that is continuous with the septum of the bulbus and the basement lamina of the male canal epithelium. Distally to the seminal vesicle the bulbus is filled with the secretory cell-necks of the prostate glands. The male canal shows three different parts: seminal duct, ejaculatory duct and eversible cirrus. At the transition of seminal duct and ejaculatory duct two prostate ducts open into the lumen. The structure of the epithelium lining the different parts of the canal is described. The transition into the cirrus may be recognized by an abrupt change in the thickness, the electron density and the stratification in the basement lamina and by the disappearance of the epithelium absent indeed in the cirrus. The material found inside the cirrus-lumen is different according to the zone considered. The origin of this material and of the cirrus teeth is discussed.Abbreviations ab- apoptotic body - ba- bacteria - bb- basal bodies of cilia - bl- basement lamina - bw- body wall - c- cilia - cb- cell body - cgp- common genital porus - ci- cirrus - cip- cirrus plug - cl- lumen of cirrus - cm- circular muscles - cr- cytoplasmatic remnants - cs- cytoplasmatic sheets - ejd- ejaculatory duct - ep_ej- epithelium of ejaculatory duct - d- desmosomes - f- flagella of spermatozoa - fd- female duct - fp- female porus - gc- golgi complex - gl- glycogen particles - hd- hemidesmosomes - lm- longitudinal muscles - ly- lysosome-like body - m- muscles - m_b- muscles of the bulbus - m_c- muscles of the cirrus - m_c- muscles of the seminal vesicle - mi- mitochondria - ml- microvilli - ms- mesenchyme - n_sd- nuclei of the seminal duct - pd- prostate duct - pg- prostate glands - ri- ribosomes - s- septum - sb- secretory vesicle - sd- seminal duct - sp- spines - sv- seminal vesicle - v- vagina - vd- vas deferens     

长足大竹象生殖系统的形态解剖研究

解剖研究了长足大竹象雌雄虫牛殖系统的构造.该虫的雌性生殖系统包括一对卵巢、一对侧输卵管、中输卵管、交配囊、受精囊、生殖腔、产卵器;雄性生殖系统由一对睾九、一对输精管、一对附腺、射精管和交配器组成.     

Specific criteria in Grania (Oligochaeta,Enchytraeidae)

The structure of the penial bulb and male efferent duct system of Grania species may be used in addition to setal pattern and spermathecal shape to distinguish species. Six penial bulb types are distinguished: (1) a simple, small, glandular bulb surrounding the male pore; (2) a small, glandular bulb, with a large, associated, dorso-medial gland mass; (3) a small glandular bulb, medial to the male pore, with an elongate male bursa (the aglandular sac), the vas deferens exitting directly into the invaginated male pore; (4) a glandular bulb with an aglandular sac and a small, cuticular stylet embedded in the bulb, extending from the ectal end of the vas deferens; (5) a glandular bulb and an aglandular sac with a long stylet extending from the vas deferens, through the bulb into the sac; and (6) glandular bulb reduced or absent, with or without an aglandular sac; with a long stylet and other prominent modifications, usually muscular, of the vas deferens. The details of the male duct structure were consistent within specimens grouped on the basis of setal distribution and shape and detailed spermathecal structure. Diverse male duct patterns are found within the polytypic species G. macrochaeta and G. postclitellochaeta. The positions of the spermathecal and male pores in their respective segments are distinctive for some species.     

Taxonomic Revision of the Marine Genera Bathydrilus Cook and Macroseta Erséus (Oligochaeta, Tubificidae), with Descriptions of Six New Species and Subspecies

Macroseta Erséus, 1975 is considered a junior synonym to Bathydrilus Cook, 1970 after examination of the type material of B. asymmetricus Cook, 1970. Bathydrilus is defined mainly by its organization of the male duct: vas deferens entering ectal half of atrium, one prostate gland attached to ectal part of atrium, near entrance of vas deferens, another prostate attached to apical, ental end of atrium. B. atlanticus sp.n., B. hadalis sp.n., B. meridianus sp.n., B. graciliatriatus sp.n. and B. longus sp.n. are described from specimens collected from various parts of the world; most of the species are deep-sea forms. Phallodrilus rohdei Jamieson, 1977 and Phallodrilus adriaticus Hrabe', 1971 are transferred to Bathydrilus , and a Caribbean/Bermudian form is described as B. adriaticus trisetosus subsp.n. The taxonomy and morphology of the different species, including B. rarisetis (Erséus, 1975) comb.n., are discussed. Bathydrilus is included in the sub-family Phallodrilinae. It appears closely related to Phallodrilus Pierantoni, 1902, from which it is distinguished principally by differences in the relative positions of the vasa deferentia, the atria and the prostate glands.     

Morphology and immunolocalization of aquaporins 1 and 9 in the agouti (Dasyprocta azarae) testis excurrent ducts

This study investigated the morphology and immunoexpression of aquaporins (AQPs) 1 and 9 in the rete testis, efferent ducts, epididymis, and vas deferens in the Azara’s agouti (Dasyprocta azarae). For this purpose, ten adult sexually mature animals were used in histologic and immunohistochemical analyses. The Azara’s agouti rete testis was labyrinthine and lined with simple cubic epithelium. Ciliated and non-ciliated cells were observed in the epithelium of the efferent ducts. The epididymal cellular population was composed of principal, basal, apical, clear, narrow, and halo cells. The epithelium lining of vas deferens was composed of the principal and basal cells. AQPs 1 and 9 were not expressed in the rete testis. Positive reaction to AQP1 was observed at the luminal border of non-ciliated cells of the efferent ducts, and in the peritubular stroma and blood vessels in the epididymis, and vas deferens. AQP9 was immunolocalized in the epithelial cells in the efferent ducts, epididymis and vas deferens. The morphology of Azara’s agouti testis excurrent ducts is similar to that reported for other rodents such as Cuniculus paca. The immunolocalization results of the AQPs suggest that the expression of AQPs is species-specific due to differences in localization and expression when compared to studies in other mammals species. The knowledge about the expression of AQPs in Azara’s agouti testis excurrent ducts is essential to support future reproductive studies on this animal, since previous studies show that AQPs may be biomarkers of male fertility and infertility.     

Neuromuscular structure of the larva to early ancestrula stages of the cyclostome bryozoan Crisia eburnea

For the first time, the development of a cyclostome bryozoan has been studied with immunochemistry and confocal laser scanning microscopy, with emphasis on nerves and muscles. The larva is covered by multiciliated cells, which are latitudinally strongly elongated and show phalloidin-stained cell junctions. We hypothesize that these cells contract at metamorphosis and squeeze the apical invagination and the adhesive sac out. Ectodermal, longitudinal muscle cells extend from the cells of the inner, conical cuticularized part of the apical invagination to the lower part of the corona, around the adhesive sac pore. These muscles are retained in the ancestrula. Scattered monociliated nerve cells are interspersed between the coronal ciliary cells. An equatorial nerve in the larva disappears at metamorphosis. The central, conical part of the cuticle becomes the terminal membrane of the ancestrula, and the underlying ectodermal and mesodermal cell layers differentiate into the polypide bud, forming a deep narrow invagination, differentiating into vestibule–atrium, mouth ring and pharynx–stomach–rectum. Tentacles develop from the ring of cells around the mouth, and a small ganglion with four nerves innervating each of the tentacles develops at the anal side of the mouth. These new findings yield further support for previous homology statements of bryozoan larvae and development.     

Effect of mating on sperm distribution in the reproductive tract of the male rat

Extragonadal sperm reserves in male rats were measured in different regions of the genital tract before and subsequent to normal ejaculation. In sexually rested rats, the sperm count (million spermatozoa for the paired organs) in different regions was: distal vas, 18; proximal vas, 9.8; cauda epididymidis, 229; caput + corpus epididymidis, 154. Following mating, the sperm count was reduced in the proximal and distal vas deferens and in the cauda epididymidis. The reproductive tract of mated females was found to contain 29% (no copulatory plug) or 59% (with copulatory plug) of the estimated mean ejaculate, which was estimated from the difference between the sperm counts in the sexually rested rat and following ejaculation. It is concluded that in the rat the immediate source of spermatozoa for ejaculation is the cauda epididymidis, with a smaller contribution arising from the vas deferens.     

Ultrastructural analysis of the functional copulatory organ of the male rotifer,Asplanchna brightwelli

The male rotifer copulatory organ is composed of a urethral canal extending from the tip of the copulatory organ internally to a layer of microvilli. The microvilli project from two different cell types, referred to as the internal and peripheral microvillar cells according to their location. At this microvillar junction a second canal, the vas deferens, continues posteriorly and enters the sperm duct region of the testis. The channel of the vas deferens is formed from the inner wall of three separate cells; the cap, intermediate and basal cells. Peripheral to these cells and parallel to them for their entire length, cross sections of seven prostate gland cells can be observed. Anteriorly, these gland cells are connected to the basal end of the microvillar layer via a short neck region, through which glandular secretion occurs only during copulation. The mechanism of secretion appears to be a form of exocytosis whereby the secretory granule membrane fuses with the cell plasmalemma so that rupturing at the point of fusion will release the granule content into the neck region. The prostate gland cells contain an abundance of autophagic vacuoles while most of the other cells of the copulatory organ contain primary lysosomes and cytolosomes. These organelles may be associated with the aging process in rotifers, or, as in the case of the prostate gland-autophagic vacuoles, with a fast organelle turnover during secretion.     

Affinity profile of the novel muscarinic antagonist, guanylpirenzepine

The study reports the functional affinity of an amidino derivative of pirenzepine, guanylpirenzepine, for muscarinic receptors mediating relaxation of rat duodenum, inhibition of rabbit vas deferens twitch contraction (both receptors previously classified as M1), guinea pig negative inotropism (M2) and ileal contraction (M3). Unlike pirenzepine, guanylpirenzepine discriminated between duodenum and vas deferens receptors, with a 30-fold greater affinity for the former subtype. The unique selectivity pattern of guanylpirenzepine (duodenum greater than vas deferens greater than ileum greater than atrium) renders it a promising tool for the classification of muscarinic receptor subtypes.