Gonadal Ducts Research Articles

Male-Predominant Carboxylesterase Expression in the Reproductive System of Molluscs and Insects: Immunochemical and Biochemical Similarity between Mytilus Male Associated Polypeptide (MAP) and Drosophila Sex-Specific Esterase S

We suggested that sexual differentiation of the reproductive system in gonochoric species of invertebrates can be characterized by common molecular mechanisms in spite of high morphological divergences of reproductive tract organs in different animal groups. The present study focused on this problem and report our observations on biochemical characteristics of male-associated polypeptide (MAP) identified in the gonad tissue of bivalve molluscs, Mytilus galloprovincialis, in comparison to those of male-specific carboxylesterase (esterase S) of Drosophila virilis ejaculatory bulbs. We provide evidences for the immunochemical similarity of Mytilus MAP and Drosophila esterase S. We also show that MAP is characterized by esterase activity toward both, α- and β-naphthyl acetates. Using immunofluorescence, we found MAP in the gonad (mantle) connective tissue, membranes of follicles and around gonad ducts but not in sperm cells. Nevertheless, the levels of MAP expression depend on presence or absence of ripe spermatozoa in the gonad follicles. In mature gonads before spawning, MAP is expressed at high level, while in the spent gonads only traces of this polypeptide could be detected. Using Western immunoblot, MAP was not observed in spermatozoa obtained by biopsy of gonad follicles. In contrast, we found this protein in spawned sperm cells. Thus, we suggest that spawning may be required to establish the trafficking mechanisms that control whether MAP is retained or excreted by the gonad. Taken together, the results indicate that MAP of M. galloprovincialis is structurally and functionally related to esterase S of D. virilis ejaculatory bulbs.

The differentiation of gonads in Anthonomus pomorum (L.) (Coleoptera: Curculionidae) larvae

The single gonad anlage in the first-instar larva of Anthonomus pomorum (L.) (Coleoptera: Curculionidae) has a form of a solid cylinder enclosed by a basal lamina, covered by the peritoneal sheath. The basal lamina lies on the gonad envelope made of a layer of flat somatic cells that surrounds a group of dozen or so germ cells and some inner somatic cells. In the second-instar, the gonad anlage is larger and divided into 2 parts connected with a band of somatic cells. Within this cellular band, the lumen of the future gonadal ducts (lateral oviducts or seminal ducts) appear. As a consequence of numerous mitoses, the gonad grows and splits into 2 parts. Each part will form one ovariole in the female or one testicular follicle in the male. In the third-instar larva, the gonocytes are gathered into several groups that are isolated by thin extensions of the somatic cells. Each part of the freshly divided gonad is connected to a tube of a developing gonadal duct. The tube joins the 2 parts of the gonad and extends towards the end of the abdomen. At the end of the third instar, the mitoses of the gonocytes do not end with complete cytokinesis; as a result, they form clusters of cells connected by the intercellular bridges. The fusomal material that fills up the individual bridges joins into one structure, forming the polyfusome.

Gonadal migration in ambiguous genitalia

Correlation of the gonadal position and mullerian duct derivative regression was estimated in 17 patients with ambiguous genitalia and dysgenetic gonads. Six out of ten testes located at or beyond the internal inguinal ring were not associated with fallopian tubes on the same side. Four of those six testes were cryptorchid, including two that were located at the internal inguinal ring. All six intra-abdominal testes were associated with an ipsilateral fallopian tube. These findings can be explained by the two-stage model of testicular descent where migration from the posterior abdominal wall to the internal inguinal ring, the transabdominal phase, is closely related to mullerian duct regression, suggesting a role for mullerian inhibiting substance in this phase.

Testicular invasion and relapse and meningeal involvement in a rat T-cell leukaemia.

During the haematogenous dissemination of this acute rat T-cell (Roser) leukaemia, infiltration of both epididymal and testicular interstitial tissue has now been demonstrated, probably as an invariable occurrence. The gonadal duct system itself was not invaded. In contrast to an earlier histopathological study with this leukaemia, meningeal invasion has also been encountered during routine passage. Furthermore, subsequent to remissions induced by carmustine (BCNU), relapse could occur as long as 80 days after the 20 day end point in control animals. This was associated with extensive infiltration of the meninges as well as in the male gonadal interstitium, the proximal epididymis being particularly vulnerable. Two doses of carmustine at intervals of one week could eradicate the disease even during the phase of logarithmic growth of the leukaemic cells, this result depending upon the level of treatment and time of dosing post-inoculation with leukaemic cells. Females carrying the disease were shown to be more readily cured than males, probably related to entry of leukaemia cells into the gonadal interstitium. This T-cell leukaemia appears to be an excellent model for the study and prospective chemotherapy of testicular relapse in acute lymphoblastic leukaemia.

Ultrasonic Imaging, a Potential Tool for Sex Determination of Live Fish

Abstract Using two conventional, medical, ultrasound imaging systems, we studied 15 juvenile and 5 mature coho salmon (Oncorhynchus kisutch) to determine if their sex could be ascertained from ultrasound images. Although liver, gut, and skeletal structures were discernible, we found the ovary and testes of the juvenile salmon difficult to identify. In mature salmon (less than 1 month from spawning), the eggs, testes, and even the male gonadal duct were clearly visible. The present study provides the first report of a technique for rapid, less-than-60-second, non-invasive identification of the sex of salmon. Our findings indicate that rapid sex determination of live fish with ultrasound is feasible.

Innervation of the male genital tract and kidney in the amphibia, Xenopus laevis Daudin, Rana temporaria L., and Bufo bufo L.

The innervation of the male genital tract and kidney in three anuran species was studied by the fluorescence histochemical method of Falck-Hillarp for the demonstration of monoamines whose identity was secured by thin-layer chromatography, and by electron microscopy including administration of 5- or 6- hydroxydopamine (5- and 6-ODHA). The genital tract comprises testis, intra- and extratesticular and intrarenal seminal efferent ducts, Bidder's canal, renal dorsal transverse ducts, and ureter. In addition--depending on the species studied--renal corpuscles and the various portions of uriniferous tubules may be involved in sperm transport. 1. Adrenaline is the main transmitter in nerves supplying the male genital tract and kidney. Only in Xenopus is it possible to demonstrate the presence of noradrenaline, which was confirmed in the chromatographic analysis. No obvious changes are observed with regard to the distribution, amount, and fluorescence intensity of adrenergic fibers and their susceptibility towards 5- and 6-OHDA when comparing animals killed in late autumn and winter, or in late spring, respectively. Non-adrenergic nerve fibers have not been observed. 2. The adrenergic innervation in the testis is only scarce and confined to blood vessels. Neuro-endocrine contacts on Leydig cells are not established. The gonadal ducts and the specific (i.e. non-vascular) are intratesticular smooth muscle cells in Xenopus are not innervated. 3. Apart from the uriniferous tubules (see below), only the ureter receives an adrenergic innervation which, however, is scarce even around the time of spermiation. Bundles of non-terminal and terminal axons are seen running contiguous to the superficial bundles of smooth muscle or smooth muscle-like cells. Neuromuscular relationships comprise synapses at distances of 2000-5--- A, but no close contacts. In the seminal vesicle of Rana the same mode of apposition of adrenergic terminals to muscle cells is observed. In addition, a direct innervation of the epithelium is seen in a few instances. 4. In the kidney the renal arteries, afferent arterioles, and the main branches of the kidney the renal arteries, afferent arterioles, and the main branches of the portal veins are supplied by a dense plexus of adrenergic nerves. Small groups of intensely fluorescent cells are found in the walls of the renal portal veins and veins proper. The density of the arteriolar plexus is more pronounced in Rana and Bufo than in Xenopus. In Rana and Bufo the arteriolar innervation comprises terminals at "ordinary" smooth musculature with membrane-to-membrane appositions, as well as contacts at a distance of 800 to 4000 A on juxtaglomerular epitheloid cells...

Morphology of Euclinostomum heterostomum (Rudolphi, 1809) Trematoda: Clinostomatidae) from Bulbicus ibis.

Adult stages ofEuclinostomum heterostomum(Rudolphi, 1809) were collected from the oral cavity and oesophagus ofBulbicusibis in Liberia, West Africa. Structural relationships within the trematodes are clarified. A prepharynx from the oral sucker leads to a well developed pharynx to which the intestinal caeca communicate via a bulb-shaped oesophagus. The origin and extent of gonadal ducts are described including a Laurer's canal, whose aperture is dorsal. A discussion of the characters previously used to differentiate species ofEuclinostomumcorroborates the views expressed by Ukoli (1996) that the genus consists of two distinct species, E.heterostomum(Rudolphi, 1809) and E.multacaecumTubangui and Maslungan, 1935. E.shrjabiniKurashvili, 1948 is proposed as a synonym of E.heterostomum. A compilation of the range in measurements of the adult and metacercarial stages of E.heterostomumis presented in the form of a table.

Preliminary observations on the acute inflammatory reaction in the Pacific oyster, Crassostrea gigas (Thunberg)

The present study was initiated to study the acute inflammatory process in the oyster, Crassostrea gigas (Thunberg), elicited by injection of turpentine into the tissues. Gross examination revealed a small greenish-yellow area of pus present in all oysters 40 hours after the injection. Histologically, the various pathological changes observable after the injection of turpentine were edema, a general leucocytic infiltration of the tissues, and congestion of the small blood channels after 8 hours. By 16 hours there was a marked vascular dilatation with pavementing of the larger vessel walls by leucocytes and a cellular exudation and migration of leucocytes toward the source of irritation at 24 hours. A thick wall of leucocytes around the wound was characteristic after 48 hours. The appearance of multinucleate giant cells began at 64 hours, as did the mass migration of leucocytes across the epithelial borders of the digestive system. By 72 hours, the digestive tubule secretory epithelium was reduced to a low cuboidal epithelium. At this time pus was becoming a prominent feature in the injured area. Necrotic changes in the gonadal area associated with edema, heavy leucocytic infiltration, distention of the gonadal ducts, and walls of leucocytes forming around the necrotic gonadal areas were observed 72 hours after injection. A distinct abscess was first observed after 88 hours and abscesses were found in almost all oysters from 88 hours through 216 hours. The consistent characteristics of the abscesses were a central area of liquefaction necrosis, surrounded by an area of necrotic leucocytes, with an area of viable appearing leucocytes around the periphery of the lesion. The abscesses were usually in the digestive tubule area and in most instances appeared well confined, even though they lacked any observable signs of fibrous encapsulation. Some oysters exhibited an ulceration of the stomach or intestinal lining. This phenomenon was not observed before 88 hours after injection, the same time at which abscesses were first noticeable.

ABNORMALITIES IN THE SEXUAL APPARATUS OF THE COMMON DOGFISH (SCYLIORHINUS CANICULUS)

SUMMARY. The present note describes six specimens of Scyliorhinus caniculus which show sexual abnormalities. Specimen 1 is an hermaphrodite fish where the gonad has presumably undergone change from the male condition. Specimens 2 and 3 show abnormal development of ducts and secondary sex characters appropriate to the opposite sex, together with unilateral inequality of the development of the sexual organs appropriate to the sex of the animal. Degeneration of the gonad and poor duct formation characterize specimens 4 to 6.

Differential Effect of Some Gonadotropic Substances on Development of Cyclical Sex Characters in the English Sparrow.

The English Sparrow, like all other wild birds of the temperate zone, has a cyclical sexuality. During the breeding season in spring and early summer the sex glands are large and active; in July or August they undergo a rapid involution. In the males the testes shrink to approximately one-thousandth of their maximal size and the ovary of the females regresses to about the condition characteristic of immature birds 2 or 3 months old. Some of the secondary sex characters, especially bill color and gonadal ducts, follow this seasonal cycle. During the period of gonadal involution the bill of the male is as light as that of a castrate and the oviduct of the female is as thin and straight as that of an immature or an ovariotomized bird. On the other hand during the breeding season the male bill is jet black and the female oviduct is voluminous and convoluted. Keck has shown that these secondary sex characters are directly controlled by the corresponding male and female sex hormones. It is evident, therefore, that the involuted gonads of fall sparrows release sex hormones either not at all or in subthreshold quantities. In an attempt to determine the possible rôle played by the hypophysis in this seasonal sex cycle, gonadotropic substances were injected into sparrows in sexual inactivity. In the winter of 1932 a group of quiescent males was injected with extracts from pregnancy urine, prepared and standardized in rat units in our own laboratory. No response was obtained, even though the exorbitant dosage of 50 units was administered daily during the whole month to some of the birds (Table I).

3. A Note upon the Gonad Ducts and Nephridia of Earthworms of the Genus Eudrilus

3. A Note upon the Gonad Ducts and Nephridia of Earthworms of the Genus Eudrilus