Schistosoma mansoni: the ultrastructure of the ducts of the male reproductive system.

Parasitology ◽  
1980 ◽  
Vol 81 (3) ◽  
pp. 565-571 ◽  
Author(s):  
Olubunmi A. Otubanjo
Keyword(s):  
Schistosoma Mansoni ◽  
Seminal Vesicle ◽  
Germ Cells ◽  
Reproductive System ◽  
Single Layer ◽  
Sperm Storage ◽  
Luminal Surface ◽  
Posterior Testis ◽  
Males And Females ◽  
Male Genital

SUMMARYThe reproductive duct of the male blood fluke Schistosoma mansoni is relatively short and undulating, extending from the most posterior testis to the beginning of the gynecophoric canal. The reproductive duct may be divided into 3 main regions which differ in ultrastructure; the vas efferens/deferens, the seminal vesicle and the cirrus tube. The epithelium of the vas efferens/deferens consists of a single layer of elongate cells with abundant convoluted lamellae on their apical surfaces. The wall of the seminal vesicle and the cirrus tube are tegumentary in nature. The basic similarities in structure of the surface tegument, the seminal vesicle and the cirrus tube suggest a common embryological origin. The presence of complex lamellae on the luminal surface suggests that the vas efferens and deferens have secretory and possibly nutritive functions apart from temporarily storing developing germ cells. The primary function of the seminal vesicle appears to be that of sperm storage; while the cirrus tube with its complex infolded wall is extensible for insemination. The presence of abundant concentrically distributed sensory papillae around the male genital pore may assist in the pairing of males and females.

scholarly journals Effects of multiple doses of simvastatin and artesunate monotherapy on SCHISTOSOMA MANSONI adult worms during infection in hyperlidemic mice

2021 ◽  
Vol 50 (1) ◽  
pp. 21-39
Author(s):  
Alba Cristina Miranda de Barros Alencar ◽  
Thais Silva dos Santos ◽  
Luciana Brandao-Bezerra ◽  
Eduardo Jose Lopes-Torres ◽  
Jose Firmino Nogueira Neto ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Schistosoma Mansoni ◽  
Reproductive System ◽  
Severe Damage ◽  
High Fat ◽  
Multiple Doses ◽  
Antischistosomal Activity ◽  
Males And Females ◽  
High Fat Chow ◽  
Scanning Electron

A single dose of simvastatin and of artesunate monotherapy cause damage to the reproductive system of schistosomes as well as severe tegumental damage in male worms recovered from mice fed high-fat chow. This study aims to investigate whether treatment with multipledose regimes may offer more antischistosomal activity advantages than single daily dosing in mice fed high-fat chow. For this purpose, nine weeks post-infection, Swiss Webster mice were gavaged with simvastatin (200 mg/kg) or artesunate (300 mg/kg) for five consecutive days and euthanized two weeks post-treatment. Adult worms were analyzed using brightfieldmicroscopy, confocal microscopy and scanning electron microscopy, presenting damages caused by simvastatin and artesunate to the reproductive system of males and females as well as tegument alterations, including peeling, sloughing areas, loss of tubercles, tegumental bubbles and tegument rupture exposing subtegumental tissue. The overall findings in this study revealed the potential antischistosomal activity of simvastatin and artesunate against Schistosoma mansoni adult worms, in addition to showing that multiple doses of either monotherapy caused severe damage to the tegument.KEY WORDS: Schistosoma mansoni; hyperlipidemia; simvastatin; artesunate; microscopy.

The Effects of the sphragis on male and female genitalia in Acraea (Nymphalidae) butterflies

2020 ◽  
Vol 22 ◽  
Author(s):  
Shannon L Summers ◽  
Akito Y Kawahara ◽  
Ana P. S. Carvalho
Keyword(s):  
Interspecific Variation ◽  
Sperm Storage ◽  
Male Mating ◽  
Museum Collections ◽  
Storage Organ ◽  
Mating Plug ◽  
Males And Females ◽  
Comparison And Analysis ◽  
Imagej Software ◽  
Sexually Antagonistic Coevolution

Male mating plugs have been used in many species to prevent female re-mating and sperm competition. One of the most extreme examples of a mating plug is the sphragis, which is a large, complex and externalized plug found only in butterflies. This structure is found in many species in the genus Acraea (Nymphalidae) and provides an opportunity for investigation of the effects of the sphragis on the morphology of the genitalia, which is poorly understood. This study aims to understand morphological interspecific variation in the genitalia of Acraea butterflies. Using specimens from museum collections, abdomen dissections were conducted on 19 species of Acraea: 9 sphragis bearing and 10 non-sphragis bearing species. Genitalia imaging was performed for easier comparison and analysis and measurements of genitalia structures was done using ImageJ software. Some distinguishing morphological features in the females were found. The most obvious difference is the larger and more externalized copulatory opening in sphragis bearing species, with varying degrees of external projections. Females of the sphragis bearing species also tend to have a shorter ductus (the structure that connects the copulatory opening with the sperm storage organ) than those without the sphragis. These differences may be due to a sexually antagonistic coevolution between the males and females, where the females evolve larger and more difficult to plug copulatory openings and the males attempt to prevent re-mating with the sphragis.

A comparative study of the reproductive system of mature, immature and ‘unisexual’ female Schistosoma mansoni

Parasitology ◽  
1973 ◽  
Vol 67 (2) ◽  
pp. 165-183 ◽  
Author(s):  
David A. Erasmus
Keyword(s):  
Comparative Study ◽  
Schistosoma Mansoni ◽  
Reproductive System ◽  
Gland Cell ◽  
Female Worm ◽  
Cortical Granules ◽  
Posterior Portion ◽  
Vitelline Duct ◽  
Vitelline Cells ◽  
Pass Through

The ultrastructure of the reproductive system of mature (54-day-old), immature (32-day-old) and females from unisexual infections of Schistosoma mansoni is described in detail. The uterus is tegumentary in structure but the vitelline duct and oviduct are complex and possess cilia as well as lamellae on their luminal surfaces. The characteristics of the cells forming the walls of the ducts suggests that they may have a digestive function. The posterior portion of the oviduct of the adult worm contains sperm which become enveloped by lamellae. The vitelline cells of the adult contain vitelline droplets, much lipid and little glycogen. A second type of body derived from endoplasmic whorls is also present. Mehlis's gland contains only one type of gland cell and these cells pass through the ootype wall and open into its lumen. The female from unisexual infections has an incompletely developed Mehlis's gland, an ovary in which the Golgi complexes do not produce typical cortical granules and has vitelline cells which remain immature. The oviduct, ootype and uterus are well developed in contrast to the vitelline duct. A comparison with young, but not inseminated worms, suggests that the presence of sperm in the oviduct is not the major stimulus which induces maturation of the female worm.

scholarly journals Chromosomal anomalies that cause male sterility in the mouse also reduce ovary size

1984 ◽  
Vol 44 (2) ◽  
pp. 219-224 ◽  
Author(s):  
Ursula Mittwoch ◽  
Shantha Mahadevaiah ◽  
Leslie A. Setterfield
Keyword(s):  
Male Sterility ◽  
Germ Cells ◽  
Reciprocal Translocation ◽  
Chromosomal Anomalies ◽  
Male Sterile ◽  
Chromosome Anomalies ◽  
Ovarian Size ◽  
Males And Females ◽  
The Difference ◽  
Ovarian Involvement

SUMMARYTwo male-sterile chromosome anomalies, the insertion Is(7; 1)40H and the tertiary trisomy, Ts(512)31H, were found to be associated with reduced ovarian volumes in immature females. Together with the reciprocal translocation, T(11; 19)42H, in which this effect was described previously, reduced ovaries have been found in all three male-sterile chromosome anomalies investigated so far, suggesting that ovarian involvement is likely to be common in these conditions. Assuming that the smaller ovarian size reflects a reduction in the number of oocytes, it is suggested that male-sterile chromosome anomalies may exert basically similar deleterious effects on meiotic germ cells in males and females, the difference in outcome being due to cell-physiological differences between spermatocytes and oocytes and to the small number of surviving oocytes required for fertility in females.

Memoirs: The Reproductive System of the Planarian Artioposthia Triangulata (Dendy)

1937 ◽  
Vol s2-80 (317) ◽  
pp. 99-125
Author(s):  
MARION L. FYFE
Keyword(s):  
Seminal Vesicle ◽  
Reproductive System ◽  
Vas Deferens ◽  
Reproductive Organs ◽  
Internal Opening ◽  
Main Subject ◽  
The Brain ◽  
Amoeboid Cells

The main subject of this paper is a detailed description of the reproductive organs of a planarian initially described by Dendy as Geoplana triangulata. Five unusual features are observed in the reproductive system: 1. The vas deferens consists of a series of wide convoluted branching tubes extending from the region of the mouth to the anterior end of the seminal vesicle. 2. The penis is very small and inconspicuous. 3. The atrium masculinum is provided with three pairs of muscular gland-organs or adenodactyli. 4. The paired ovaries are situated one on each side of the seminal vesicle, not in the region of the brain as is usual. 5. Each ovary is a long fusiform body enclosing more than one true ovary or germarium, as well as specialized parovarian and amoeboid cells which are probably nutritive, and are associated with the internal opening of the oviduct. The writer refers Geoplana triangulata Dendy to the genus Artioposthia owing to the presence of adenodactyli in the atrium masculinum. Each adenodactylus encloses a glandular reservoir from which a ciliated duct leads to the atrial cavity. The actual function of the adenodactyli is obscure, but the very small size of the penis and the fact that the adenodactyli are extrusible suggests the possibility of these latter performing the function of a penis.

Vascular Biology, Thromboresistance, and Inflammation

2006 ◽  
Author(s):  
Richard C. Becker ◽  
Frederick A. Spencer
Keyword(s):  
Endothelial Cells ◽  
Cardiovascular System ◽  
Vascular Endothelium ◽  
Vascular Endothelial Cells ◽  
Surface Membrane ◽  
Single Layer ◽  
Intercellular Junctions ◽  
Cell Junctions ◽  
Luminal Surface ◽  
Internal Layers

The delivery of vital substrate to metabolically active tissues and vital organs is achieved and maintained by the cardiovascular system including the heart, macrovasculature, and microvasculature. This life-sustaining process requires a normally functioning vascular endothelium—a multifunctional organ system composed of physiologically responsive cells responsible for vasomotion (vascular tone), thromboresistance, and inflammoresistance. Simply by virtue of its anatomic location, the vascular endothelium is functionally complex. It defines the intra- and extravascular components, serves as a selectively permeable barrier, and provides a continuous lining to the cardiovascular system. The location of the vascular endothelium is vital to its biologic interactions with cells found within the circulation and to the vessel wall itself. The surface activity is augmented in the microcirculation, also known as the resistance bed, where the ratio of endothelial surface to circulating blood is maximal. In most vertebrates, vascular endothelial cells form a single layer of squamous lining cells (0.1–0.5 μm in thickness) joined by intercellular junctions. The cells themselves are polygonal (varying between 10 and 50 μm) and are positioned in the long axis of the vessel, orienting the cellular longitudinal dimension in the direction of blood flow. The endothelial cell has three surfaces: luminal (nonthrombogenic), subluminal (adhesive), and cohesive. The luminal surface is devoid of electron-dense connective tissue. It does, however, possess an exterior coat (or glycocalyx), consisting primarily of starches and proteins secreted by the endothelial cells. Plasma proteins, including lipoprotein lipase, α2-macroglobulin, heparin cofactor II, antithrombin, and albumin, as well as small amounts of fibrinogen and fibrin are adsorbed to the luminal surface. The surface membrane itself adds significantly to thromboresistance by carrying a negative charge that repels similarly charged circulating blood cells. The subluminal (or abluminal) surface adheres to subendothelial connective tissues. Small processes penetrate through a series of internal layers to form myoendothelial junctions with subjacent smooth muscle cells. The cohesive component of the vascular endothelium connects individual endothelial cells to one another by cell junctions of two basic types: occluding (tight) junctions and communicating (gap) junctions. Occluding junctions represent a physical link between adjacent cells, sealing the intercellular space.

Mechanism and Ecological Significance of Sperm Storage in the Northern Fulmar with Reference to Its Occurrence in Other Birds

The Auk ◽  
1983 ◽  
Vol 100 (3) ◽  
pp. 593-600 ◽  
Author(s):  
Scott A. Hatch
Keyword(s):  
Sexual Behavior ◽  
Reproductive System ◽  
Sperm Storage ◽  
Egg Laying ◽  
Ecological Significance ◽  
Northern Fulmar ◽  
Male And Female ◽  
Fulmarus Glacialis ◽  
Oceanodroma Leucorhoa ◽  
Horned Puffin

Abstract Sperm-storage glands were found in the uterovaginal (UV) region of the oviduct in Northern Fulmars (Fulmarus glacialis), Horned Puffins (Fratercula corniculata), and Leach's Storm-Petrels (Oceanodroma leucorhoa) collected before or shortly after egg laying. Previously described only in domestic Galliformes, UV sperm-storage glands may prove to be a common feature of the avian reproductive system. There is as yet no compelling explanation of their function in the Horned Puffin. In the Northern Fulmar, and probably in other petrels, however, sperm-storage glands allow the separation of the male and female over pelagic waters for several weeks immediately before egg laying. The likelihood of prolonged viability of sperm in the female reproducitve tract should be considered in interpreting the sexual behavior of other wild birds.

A new description of the reproductive system of Schistosoma mansoni (Trematoda: Schistosomatidae) analyzed by confocal laser scanning microscopy

2004 ◽  
Vol 95 (1) ◽  
pp. 43-49 ◽  
Author(s):  
Renata Heisler Neves ◽  
Carla de Lamare Biolchini ◽  
José Roberto Machado-Silva ◽  
Jorge José Carvalho ◽  
Thiago Braga Branquinho ◽  
...  
Keyword(s):  
Schistosoma Mansoni ◽  
Confocal Laser Scanning Microscopy ◽  
Reproductive System ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser Scanning ◽  
Scanning Microscopy ◽  
Confocal Laser

scholarly journals Extreme fertilization bias towards freshly inseminated sperm in a species exhibiting prolonged female sperm storage

2018 ◽  
Vol 5 (3) ◽  
pp. 172195 ◽  
Author(s):  
Clelia Gasparini ◽  
Emma Daymond ◽  
Jonathan P. Evans
Keyword(s):  
Artificial Insemination ◽  
Poecilia Reticulata ◽  
Sperm Storage ◽  
Sperm Precedence ◽  
Control Potential ◽  
Complete Dominance ◽  
Poeciliid Fish ◽  
Behavioural Interactions ◽  
Males And Females ◽  
Reproductive Cycles

The storage of sperm by females across successive reproductive cycles is well documented in internal fertilizers, yet the fate of stored sperm when they compete with ‘new’ sperm to fertilize a female's eggs has rarely been considered. This gap in our understanding is likely due to the logistical difficulties of controlling behavioural interactions during or after mating, which in turn may influence how many sperm are inseminated and how stored sperm are ultimately used during successive bouts of sperm competition with freshly inseminated sperm. Here, we use artificial insemination (AI) in guppies ( Poecilia reticulata ), a polyandrous live-bearing poeciliid fish exhibiting prolonged sperm storage by females, to overcome these challenges. The use of AI enables us to control potential differential maternal effects (e.g. behaviourally mediated cryptic female choice) and specifically test for post-copulatory paternity biases that favour either stored or fresh sperm when they compete to fertilize eggs. Our paternity analyses revealed the almost complete dominance of freshly inseminated sperm over stored sperm, supporting previous studies reporting similar patterns following natural matings across successive brood cycles. However, our use of AI, which excluded behavioural interactions between males and females, most likely generated a far stronger pattern of fresh sperm precedence compared with those reported in previous studies, possibly implicating ‘cryptic' forms of selection by females that may sometimes bolster the success of stored sperm.

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