The absorptive surfaces of Nectonema sp. (Nematomorpha: Nectonematoidea) from Pandalus montagui: histology, ultrastructure, and absorptive capabilities of the body wall and intestine

1988 ◽  
Vol 66 (2) ◽  
pp. 289-295 ◽  
Author(s):  
Barbara Skaling ◽  
B. M. MacKinnon
Keyword(s):  
Body Wall ◽  
The Body ◽  
Secretory Cells ◽  
Intestinal Cells ◽  
Dense Granules ◽  
Blind Ending ◽  
Carrier Mediated Transport ◽  
Passamaquoddy Bay ◽  
Juvenile Stages

The histology, ultrastructure, and absorptive capabilities of the body wall and intestine of the juvenile stages of Nectonema sp. (Nematomorpha: Nectonematoidea) that parasitize the shrimp Pandalus montagui in Passamaquoddy Bay, New Brunswick, were examined using histological, histochemical, ultrastructural, and in vitro labeling techniques. The body wall consists of a multilayered cuticle that rests on, and is produced by, a thin cellular hypodermis. The intestinal tract consists of a minute mouth, a cuticularized oesophagus, and a blind-ending intestine consisting of a lumen surrounded at different places by two, three, or four elongated cells. These cells consists of a maximum of two "absorptive" cells with microvillar luminal surfaces, and a maximum of two "secretory" cells, which contain numerous electron-dense granules. Acid and alkaline phosphatases and nonspecific esterases were detected in the outer layers of the body wall (cuticle and hypodermis) and in the intestinal cells. Such enzymes appear to be related to absorption of nutrient substances. Autoradiography experiments using [3H]leucine showed that following incubation in [3H]leucine-labeled seawater, leucine was concentrated in the hypodermis and the intestinal cells. Similar results were obtained when worms were incubated first in [3H]leucine-labeled seawater and then chased in nonlabeled L-leucine. Uptake of [3H]leucine was inhibited by L-leucine when worms were incubated in a seawater solution of [3H]leucine and excess L-leucine. In vitro absorption of [3H]leucine provides evidence that a carrier-mediated transport system operates across both the cuticle and the intestine of Nectonema sp.

The cuticle of adultNippostrongylus brasiliensis

Parasitology ◽  
1965 ◽  
Vol 55 (1) ◽  
pp. 173-181 ◽  
Author(s):  
D. L. Lee
Keyword(s):  
Electron Microscope ◽  
Body Wall ◽  
Technical Assistance ◽  
Cortical Layer ◽  
The Body ◽  
Collagen Fibrils ◽  
Intestinal Cells ◽  
Nippostrongylus Brasiliensis ◽  
Normal Appearance

The cuticle of adults ofNippostrongylus brasiliensishas been described using histological, histochemical and ultrastructural techniques.The cuticle has the following layers: an outer triple-layered membrane; a single cortical layer; a fluid-filled layer which is traversed by numerous collagen fibrils; struts which support the fourteen longitudinal ridges of the cuticle and which are suspended by collagen fibrils in the fluid-filled layer; two fibre layers, each layer apparently containing three layers of fibres; and a basement lamella.The fluid-filled layer contains haemoglobin and esterase.The muscles of the body wall are attached to either the basement lamella or to the fibre layers of the cuticle.The mitochondria of the hypodermis are of normal appearance.The longitudinal ridges of the cuticle appear to abrade the microvilli of the intestinal cells of the host.Possible functions of the cuticle are discussed.I wish to thank Dr P. Tate, in whose department this work was done, for helpful suggestions and criticism at all stages of this work, and Mr A. Page for technical assistance. I also wish to thank Professor Boyd for permission to use the electron microscope in the Department of Anatomy.

Chemical characterization and in vitro biological activity of Cymbopogon citratus extracts against Haemonchus spp. and Trichostrongylus spp. nematodes from sheep

Parasitology ◽  
2020 ◽  
Vol 147 (13) ◽  
pp. 1559-1568
Author(s):  
Letícia Oliveira da Rocha ◽  
Gloria Cristina da Silva Lemos ◽  
Ivo José Curcino Vieira ◽  
Raimundo Braz-Filho ◽  
Silvério de Paiva Freitas ◽  
...  
Keyword(s):  
Biological Activity ◽  
Chemical Characterization ◽  
Gastrointestinal Nematodes ◽  
The Body ◽  
Intestinal Cells ◽  
Phytochemical Analysis ◽  
Cymbopogon Citratus ◽  
Thin Sections ◽  
Methanolic Extracts

AbstractMedicinal plants have been the focus of several studies due to their nematicide properties which can be used to control nematodes in sheep. No study has examined the morphological effects of Cymbopogon citratus on nematodes. Thus, this study evaluated the chemical composition, nematicidal activity and effects of C. citratus extracts on the morphology of eggs and infective larvae (L3) of sheep. Aqueous and methanolic extracts and fractions of C. citratus were obtained and analysed in vitro. The C. citratus extracts were effective against Haemonchus spp. and Trichostrongylus spp. larvae and eggs. Ten fractions were obtained from C. citratus, six of which had high ovicidal activity at 1000 μg mL−1, and two fractions had high activity at all tested concentrations. The phytochemical analysis identified the presence of compounds such as terpenoids, various ketones, esters, and fatty acids. The ultrastructural analysis showed deformations of the cuticle and wilting along the body of the nematodes at all concentrations. The muscular layer, intestinal cells and the mitochondria profile showed damage compared to the typical pattern. Ultra-thin sections of eggs treated with methanolic fractions of C. citratus presented modifications. This study showed the biological activity and effects of C. citratus on the gastrointestinal nematodes in sheep.

Infection of Meloidogyne javanica by Paecilomyces lilacinus

Nematology ◽  
1999 ◽  
Vol 1 (2) ◽  
pp. 131-139 ◽  
Author(s):  
Rita Holland ◽  
Keith Williams ◽  
Alamgir Khan
Keyword(s):  
Body Wall ◽  
Meloidogyne Javanica ◽  
The Body ◽  
Paecilomyces Lilacinus ◽  
Adult Females ◽  
In Vitro Interaction

AbstractThe in vitro interaction of Paecilomyces lilacinus strain 251 with eggs, 3rd and 4th stage juveniles and adult females of Meloidogyne javanica was studied. Eggs of all stages, including those containing unhatched juveniles, were infected by P. lilacinus. Infection of eggs occurred following flattening of hyphae to the egg surface and formation of appressoria. Sometimes these occurred within extensive networks of hyphae of the egg surface. Hyphae later grew out of the egg to continue growing or form conidiophores. Third and 4th stage juveniles and adult females were readily infected, with hyphae and conidiophores penetrating the body wall. Die Infektion von Meloidogyne javanica durch Paecilomyces lilacinus - Es wurden die in vitro auftretenden Wechselwirkungen zwischen Paecilomyces lilacinus Stamm 251 und den Eiern, J3, J4 und adulten Weibchen von Meloidogyne javanica untersucht. Eier wurden in allen Stadien von P. lilacinus infiziert einschliesslich der ungeschlupfte J2 enthaltenden Eier. Die Infektion erfolgte anschliessend an eine Abflachung von Hyphen auf der Eioberflache und eine Appressorienbildung. Manchmal erschienen diese innerhalb eines ausgedehnten Netzwerkes von Hyphen auf der Eioberflache. Spater wuchsen Hyphen aus dem Ei heraus, wuchsen weiter oder bildeten Konidiophoren. Juvenile des dritten oder vierten Stadiums und adulte Weibchen wurden ohne weiteres befallen, wobei Hyphen und Konidiophoren durch die Korperwand drangen.

scholarly journals Serotonin modulates muscle function in the medicinal leech Hirudo verbana

2011 ◽  
Vol 7 (6) ◽  
pp. 885-888 ◽  
Author(s):  
Shannon P. Gerry ◽  
David J. Ellerby
Keyword(s):  
Body Wall ◽  
Longitudinal Muscle ◽  
Force Production ◽  
Physiological Saline ◽  
The Body ◽  
Hirudo Verbana ◽  
Work Production ◽  
Large Length ◽  
Body Wall Muscles

The body wall muscles of sanguivorous leeches power mechanically diverse behaviours: suction feeding, crawling and swimming. These require longitudinal muscle to exert force over an extremely large length range, from 145 to 46 per cent of the mean segmental swimming length. Previous data, however, suggest that leech body wall muscle has limited capacity for force production when elongated. Serotonin (5-HT) alters the passive properties of the body wall and stimulates feeding. We hypothesized that 5-HT may also have a role in allowing force production in elongated muscle by changing the shape of the length–tension relationship (LTR). LTRs were measured from longitudinal muscle strips in vitro in physiological saline with and without the presence of 10 µM 5-HT. The LTR was much broader than previously measured for leech muscle. Rather than shifting the LTR, 5-HT reduced passive muscle tonus and increased active stress at all lengths. In addition to modulating leech behaviour and passive mechanical properties, 5-HT probably enhances muscle force and work production during locomotion and feeding.

Larval and Juvenile Stages of the Isopod Holophryxus alaskensis (Epicarida, Dajidae) Parasitic on Decapods

1981 ◽  
Vol 38 (11) ◽  
pp. 1438-1443 ◽  
Author(s):  
Kenneth O. Coyle ◽  
George J. Mueller
Keyword(s):  
Intermediate Host ◽  
Body Wall ◽  
Dorsal Side ◽  
Juvenile Stage ◽  
The Body ◽  
Juvenile Stages

Complete descriptions of the epicarid, microniscid, cryptoniscid, and juvenile stages of Holophryxus alaskensis are given. The epicarid differs from other epicarids by its chelate pereopods. The intermediate host is Euchaeta elongate (Copepoda). The cryptoniscid stage differs from others of the Dajidae in lacking a buccal sucker and posterior projection on article 1 of antenna 1. The cryptoniscid attaches to the body wall beneath the carapace of Pasiphaea pacifica (Decapoda), where it metamorphoses to the juvenile stage before migrating to the dorsal side of the carapace.Key words: Isopoda, Epicarida, Dajidae, cryptoniscid, epicarid, microniscid, parasite, Decapoda

scholarly journals The two actin-interacting protein 1 genes have overlapping and essential function for embryonic development in Caenorhabditis elegans

2011 ◽  
Vol 22 (13) ◽  
pp. 2258-2269 ◽  
Author(s):  
Shoichiro Ono ◽  
Kazumi Nomura ◽  
Sadae Hitosugi ◽  
Domena K. Tu ◽  
Jocelyn A. Lee ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Actin Filament ◽  
Actin Filaments ◽  
Body Wall ◽  
The Body ◽  
Body Wall Muscle ◽  
Interacting Protein ◽  
Adult Muscle ◽  
Essential Function

Disassembly of actin filaments by actin-depolymerizing factor (ADF)/cofilin and actin-interacting protein 1 (AIP1) is a conserved mechanism to promote reorganization of the actin cytoskeleton. We previously reported that unc-78, an AIP1 gene in the nematode Caenorhabditis elegans, is required for organized assembly of sarcomeric actin filaments in the body wall muscle. unc-78 functions in larval and adult muscle, and an unc-78–null mutant is homozygous viable and shows only weak phenotypes in embryos. Here we report that a second AIP1 gene, aipl-1 (AIP1-like gene-1), has overlapping function with unc-78, and that depletion of the two AIP1 isoforms causes embryonic lethality. A single aipl-1–null mutation did not cause a detectable phenotype. However, depletion of both unc-78 and aipl-1 arrested development at late embryonic stages due to severe disorganization of sarcomeric actin filaments in body wall muscle. In vitro, both AIPL-1 and UNC-78 preferentially cooperated with UNC-60B, a muscle-specific ADF/cofilin isoform, in actin filament disassembly but not with UNC-60A, a nonmuscle ADF/cofilin. AIPL-1 is expressed in embryonic muscle, and forced expression of AIPL-1 in adult muscle compensated for the function of UNC-78. Thus our results suggest that enhancement of actin filament disassembly by ADF/cofilin and AIP1 proteins is critical for embryogenesis.

scholarly journals Biology and predatory attributes of a diplogasterid nematode, Fictor composticola Khan et al., 2008

2015 ◽  
Vol 52 (1) ◽  
pp. 50-57 ◽  
Author(s):  
H. K. Bajaj ◽  
R. S. Kanwar
Keyword(s):  
Body Wall ◽  
The Body ◽  
Button Mushroom ◽  
Intestinal Contents ◽  
Aphelenchus Avenae ◽  
Stage Juvenile ◽  
Oesophageal Bulb ◽  
Biocontrol Potential ◽  
Egg Shell

Summary Biology of Fictor composticola has been studied on Aphelenchus avenae in vitro. It reproduces by amphimixis, embryonic development is completed in 24 - 27 h and life cycle in 3 - 4 days. Fusion of sperm and egg pronuclei occurs in the uteri. Pulsation of median oesophageal bulb and pressing of lips against egg shell is seen just prior to hatching but teeth seem to play no role in this process. No moulting occurs inside the egg shell and the first stage juvenile hatches out. Female and male undergo mating upon addition of water in the culture plates and continue to swim in copula for a considerable time. A female lays 1.6 - 4.0 eggs in 24 h while feeding upon A. radicicolus. Predation and reproduction is affected by the temperature and 25 - 35 °C is the optimum range for these phenomena. Process of feeding as recorded with a CCTV attached to a compound microscope is described. F. composticola engulfs small preys; sucks the intestinal contents while holding them or cuts the body wall of large-sized preys and then feeds on prolapsed organs. Two sexes differ in their efficiencies of predation, a female on an average kills 53 A. avenae as compared to 11 by a male in 24 h. F. composticola feeds and reproduces on mycophagous nematodes and juveniles of root- knot, cyst and citrus nematodes but does not prey upon adult nematodes having coarsely annulated cuticle. Cannibalism in this species is also observed. F. composticola and Seinura paratenuicaudata prey upon each other. Biocontrol potential of F. composticola for managing nematode problems in button mushroom and agricultural crops has also been discussed.

The Blood-system in the Serpulimorpha (Annelida, Polychaeta)

1950 ◽  
Vol s3-91 (14) ◽  
pp. 111-129
Author(s):  
JEAN HANSON
Keyword(s):  
Body Wall ◽  
Ventral Surface ◽  
Blood System ◽  
The Body ◽  
Sphincter Muscle ◽  
Central System ◽  
Respiratory Organ ◽  
Blind Ending ◽  
Usual Manner ◽  
Vascular Plexuses

1. An account will be given of the anatomy of the blood-system of Pomatoceros triqueter, and of comparative observations on the following serpulids: Serpula vermicularis, S. lo-biancoi, Hydroides norvegica, Vermiliopsis infundibulum, Salmacina incrustans, Protula intestinum, P. tubularia, Apomatus ampulliferus, A. similis, Spirorbis militaris, and S. corrugatus. 2. In all species there is a central blood-system of large vessels in which blood circulates in the usual manner, and a peripheral system of small blind-ending vessels which are alternately full and empty, receiving their blood from the central system, then returning it along the same channels to the central system. 3. The central blood-system is as follows: Blood moves from the tip of the abdomen to the front of the thorax through a sinus enveloping the alimentary canal. Anteriorly it passes through dorsal, transverse, and circum-oesophageal vessels to a ventral vessel in which it moves backwards to the tip of the abdomen. A pair of ring vessels connects the ventral vessel with the sinus at the posterior end of each segment. 4. The anterior end of the dorsal vessel in Pomatoceros triqueter, Serpula vermicularis, Hydroides norvegica, and Vermiliopsis infundibulum is surrounded by a sphincter muscle of unknown function, and contains a muscular valve which probably obstructs the back-flow of blood from the transverse vessel. Protula intestinum possesses the valve but lacks the sphincter. Salmacina incrustans and Spirorbis militaris have neither valve nor sphincter. 5. The peripheral blood-system has the following components: the branchial vessels with branches in the crown; the vessels of the collar and lips; the peri-oesophageal plexuses; the trans-septal vessels supplying the body-wall, parapodia, and thoracic membrane. 6. In Pomatoceros triqueter the opercular vessel is spirally coiled, but in other serpulids it is characteristically branched. 7. When Pomatoceros withdraws into its tube, movement of blood in the crown ceases. The operculum is therefore not used as a special respiratory organ when the crown is retracted. 8. The oesophagus of Pomatoceros is surrounded by two independent blind-ending vascular plexuses, an outer plexus communicating with the gut sinus and an inner plexus with the circum-oesophageal vessels. Serpula vermicularis is probably the same. Hydroides norvegica and Protula intestinum lack the outer plexus. Salmacina and Spirorbis have neither plexus. 9. The body-wall of each segment derives its blood-supply from trans-septal branches of the ring vessels of the preceding segment. In Salmacina and Spirorbis these trans-septal vessels are unbranched. In larger serpulids they have numerous branches under the epidermis, in the parapodia, and in some cases on the coelomic surface of the body-wall. Branches of the thoracic trans-septal vessels supply the thoracic membrane. In all species except Salmacina, Spirorbis, and Protula intestinum he thoracic trans-septal vessels end ventrally in two superficial ventro-lateral longitudinal vessels which communicate either with the circum-oesophageal vessels or with the ventral vessel. In P. intestinum the thoracic trans-septal vessels enter the ventral vessel directly. The pattern of superficial vessels on the ventral surface of the thorax is useful for identifying specimens. 10. Lateral vessels, such as are found in Sabella, are absent in all serpulids.

Observations on the epidermis of the miracidium and on the formation of the tegument of the sporocyst of Fasciola hepatica

Parasitology ◽  
1970 ◽  
Vol 61 (2) ◽  
pp. 177-190 ◽  
Author(s):  
V. R. Southgate
Keyword(s):  
Plasma Membrane ◽  
Basal Lamina ◽  
Body Wall ◽  
Fasciola Hepatica ◽  
Epidermal Cells ◽  
The Body ◽  
Transitional Epithelium ◽  
Dense Granules ◽  
Outer Covering ◽  
Body Wall Muscles

The relationship between the ciliated epidermal cells and the subepidermal layer of the miracidium of Fasciola hepatica has been described. Non-ciliated ridge-like extensions of the subepidermal layer separate the ciliated epidermal cells from each other. The sunken portions of the subepidermal layer, each containing a nucleus, lie below the outer body wall muscles of the miracidium and open into the ridge by narrow neck-like connexions. Elongate vesicles, which may be a source of stored plasma membrane similar to that which occurs in the transitional epithelium of other animals, fill most of the ridge. In addition, characteristic round electron dense granules are found in the ridge but the majority are found in the sunken portions of the subepidermal layer.The development and origins of the tegument of the sporocyst of F. hepatica have been described at the ultrastructural level. When the miracidium is in the process of penetrating the snail host, large vacuoles appear between the ciliated epidermal cells and the basal lamina which overlies the muscles of the body wall. These vacuoles have the effect of loosening the epidermal cells from the basal lamina of the body wall of the miracidium. Possible mechanisms involved in the formation of such vacuoles are suggested and discussed.During penetration of the snail the ciliated epidermal cells of the miracidium are lost; the ridge, a syncytial layer between the epidermal cells which is connected with the subepidermal layer, spreads over the basal lamina and exposed body wall muscles of the metamorphosing sporocyst to form the new outer covering of the sporocyst.Cytoplasm passes from the subtegumentary layer into the tegument during this stage of the development of the body wall of the sporocyst. Muscular contraction and microtubules may be involved in the outward movements of this cytoplasm. The nuclei of the subtegumentary layer remain below the muscles of the body wall.Twenty-four hours after penetration of the snail the outer plasma membrane of the tegument forms folds, which greatly increase the surface area.Sixty hours after penetration involutions between the folds, which may indicate pinocytosis, are present, and it is suggested that pinocytosis may play a role in food absorption.The fully formed tegument is a syncytial layer containing numerous electron dense granules, vacuoles, mitochondria and lipid droplets.The results on the formation of the tegument of the sporocyst have been discussed with reference to the controversy about the origins and terminology of the outer covering of the Platyhelminths.

scholarly journals Two Caenorhabditis elegans calponin-related proteins have overlapping functions to maintain cytoskeletal integrity and are essential for reproduction

2020 ◽  
Author(s):  
Shoichiro Ono ◽  
Kanako Ono
Keyword(s):  
Caenorhabditis Elegans ◽  
Actin Filaments ◽  
Body Wall ◽  
The Body ◽  
Body Wall Muscle ◽  
Related Protein ◽  
Somatic Gonad ◽  
Related Proteins

AbstractMulticellular organisms have multiple genes encoding calponins and calponin-related proteins, and some of these are known to regulate actin cytoskeletal dynamics and contractility. However, functional similarities and differences among these proteins are largely unknown. In the nematode Caenorhabditis elegans, UNC-87 is a calponin-related protein with seven calponin-like (CLIK) motifs and is required for maintenance of contractile apparatuses in muscle cells. Here, we report that CLIK-1, another calponin-related protein that also contains seven CLIK motifs, has an overlapping function with UNC-87 to maintain actin cytoskeletal integrity in vivo and has both common and different actin-regulatory activities in vitro. CLIK-1 is predominantly expressed in the body wall muscle and somatic gonad, where UNC-87 is also expressed. unc-87 mutation causes cytoskeletal defects in the body wall muscle and somatic gonad, whereas clik-1 depletion alone causes no detectable phenotypes. However, simultaneous depletion of clik-1 and unc-87 caused sterility due to ovulation failure by severely affecting the contractile actin networks in the myoepithelial sheath of the somatic gonad. In vitro, UNC-87 bundles actin filaments. However, CLIK-1 binds to actin filaments without bundling them and is antagonistic to UNC-87 in filament bundling. UNC-87 and CLIK-1 share common functions to inhibit cofilin binding and allow tropomyosin binding to actin filaments, suggesting that both proteins stabilize actin filaments. Thus, partially redundant functions of UNC-87 and CLIK-1 in ovulation is likely mediated by their common actin-regulatory activities, but their distinct activities in actin bundling suggest that they also have different biological functions.

Sign in / Sign up

Export Citation Format

Share Document