Pigments of Chaetopterus variopedatus (polychaeta)

1959 ◽  
Vol 150 (941) ◽  
pp. 509-538 ◽  
Keyword(s):  
Body Wall ◽  
Histological Study ◽  
The Body ◽  
Bile Pigment ◽  
Green Pigment ◽  
Chaetopterus Variopedatus ◽  
Pigment Type ◽  
Constant Feature ◽  
Chlorophyll Derivatives

A chemical and histological study has been made of the pigments of the polychaete worm Chaetopterus variopedatus . The conspicuous green colour of the gut in the middle and posterior regions is due to a green pigment hitherto known as ‘chaetopterin’, which is localized in small green spherules in the gut epithelial cells. ‘Chaetopterin’ is a mixture of phaeophorbides a and b , the former predominating. Other pigments found in the gut-wall of the middle region of the worm include the chlorophyll derivatives iso -phaeophorbide d , dioxymesophyllochlorin, copper phaeophorbide chelation compounds, and possibly rhodoporphyrin g 7 carboxylic acid; coproporphyrin III; bile pigment-type compounds turbo-glaucobilin and helioporobilin, and the carotenoids β -carotene and traces of a xanthophyll. The body wall contains β -carotene. A black melanin is present in the black chaetae of setigerous segment IV, and a reddish melanoid pigment in a red stripe at the anterior margin of the head. Pigments present in the faeces include phaeophorbides and β -carotene. The phaeophorbides a and b are derived from chlorophylls a and b in the animal’s food (detritus). The green spherules in vivo are not fluorescent, suggesting that fluorescent, suggesting that the pigment is adsorbed on to some large molecule, possibly a mucopolysaccharide. No evidence was found that the green spherules are symbionts. Since they are such a constant feature of the animals, even during prolonged starvation, they would appear to play some essential biochemical role.

Paramyosin isoforms of Schistosoma mansoni are phosphorylated and localized in a large variety of muscle types

Parasitology ◽  
1996 ◽  
Vol 112 (5) ◽  
pp. 459-467 ◽  
Author(s):  
J. Schmidt ◽  
O. Bodor ◽  
L. Gohr ◽  
W. Kunz
Keyword(s):  
Schistosoma Mansoni ◽  
Specific Antibody ◽  
Body Wall ◽  
Uranyl Acetate ◽  
The Body ◽  
Striated Muscles ◽  
Western Blots ◽  
Muscle Types ◽  
Longitudinal Muscles

SUMMARYParamyosin, although a widely distributed muscle component among invertebrates, has hitherto not clearly been shown to occur in the muscles of schistosomes. Instead, it has been reported to occur in the tegument. In the present study, a specific antibody reacting with each of 10 isoforms of paramyosin was used for light microscopical immunolocalization in sections of Schistosoma mansoni. Specimens were fixed by a new method to immobilize antigens with uranyl acetate–trehalose–methanol. In cercariae, schistosomula, and adults, the circular and longitudinal muscles of the body wall, the dorsoventral muscles and those surrounding the gut and the pharynx as well as the fast moving cross-striated muscles of the tail of cercariae intensely reacted with the antibody. However, neither immunohistologically nor on Western blots of isolated tegument, were indications found for the presence of paramyosin in the tegument. In vivo phosphorylation and binding of anti-phospho-tyrosine and anti-phospho-serine antibodies show phosphorylation of paramyosin which probably is responsible for the generation of the isoforms.

Growth cones stall and collapse during axon outgrowth in Caenorhabditis elegans

Development ◽  
1999 ◽  
Vol 126 (20) ◽  
pp. 4489-4498 ◽  
Author(s):  
K.M. Knobel ◽  
E.M. Jorgensen ◽  
M.J. Bastiani
Keyword(s):  
Caenorhabditis Elegans ◽  
Growth Cone ◽  
Nerve Cord ◽  
Body Wall ◽  
Growth Cones ◽  
The Body ◽  
Axon Outgrowth ◽  
Attachment Structures ◽  
Dorsal Nerve

During nervous system development, neurons form synaptic contacts with distant target cells. These connections are formed by the extension of axonal processes along predetermined pathways. Axon outgrowth is directed by growth cones located at the tips of these neuronal processes. Although the behavior of growth cones has been well-characterized in vitro, it is difficult to observe growth cones in vivo. We have observed motor neuron growth cones migrating in living Caenorhabditis elegans larvae using time-lapse confocal microscopy. Specifically, we observed the VD motor neurons extend axons from the ventral to dorsal nerve cord during the L2 stage. The growth cones of these neurons are round and migrate rapidly across the epidermis if they are unobstructed. When they contact axons of the lateral nerve fascicles, growth cones stall and spread out along the fascicle to form anvil-shaped structures. After pausing for a few minutes, they extend lamellipodia beyond the fascicle and resume migration toward the dorsal nerve cord. Growth cones stall again when they contact the body wall muscles. These muscles are tightly attached to the epidermis by narrowly spaced circumferential attachment structures. Stalled growth cones extend fingers dorsally between these hypodermal attachment structures. When a single finger has projected through the body wall muscle quadrant, the growth cone located on the ventral side of the muscle collapses and a new growth cone forms at the dorsal tip of the predominating finger. Thus, we observe that complete growth cone collapse occurs in vivo and not just in culture assays. In contrast to studies indicating that collapse occurs upon contact with repulsive substrata, collapse of the VD growth cones may result from an intrinsic signal that serves to maintain growth cone primacy and conserve cellular material.

Calsequestrin, a calcium sequestering protein localized at the sarcoplasmic reticulum, is not essential for body-wall muscle function in Caenorhabditis elegans

2000 ◽  
Vol 113 (22) ◽  
pp. 3947-3958 ◽  
Author(s):  
J.H. Cho ◽  
Y.S. Oh ◽  
K.W. Park ◽  
J. Yu ◽  
K.Y. Choi ◽  
...  
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Calcium Binding ◽  
Body Wall ◽  
Functional Characterization ◽  
The Body ◽  
Body Wall Muscle ◽  
C Elegans ◽  
Muscle Formation ◽  
Body Wall Muscles

Calsequestrin is the major calcium-binding protein of cardiac and skeletal muscles whose function is to sequester Ca(2+)in the lumen of the sarcoplasmic reticulum (SR). Here we describe the identification and functional characterization of a C. elegans calsequestrin gene (csq-1). CSQ-1 shows moderate similarity (50% similarity, 30% identity) to rabbit skeletal calsequestrin. Unlike mammals, which have two different genes encoding cardiac and fast-twitch skeletal muscle isoforms, csq-1 is the only calsequestrin gene in the C. elegans genome. We show that csq-1 is highly expressed in the body-wall muscles, beginning in mid-embryogenesis and maintained through the adult stage. In body-wall muscle cells, CSQ-1 is localized to sarcoplasmic membranes surrounding sarcomeric structures, in the regions where ryanodine receptors (UNC-68) are located. Mutation in UNC-68 affects CSQ-1 localization, suggesting that the two possibly interact in vivo. Genetic analyses of chromosomal deficiency mutants deleting csq-1 show that CSQ-1 is not essential for initiation of embryonic muscle formation and contraction. Furthermore, double-stranded RNA injection resulted in animals completely lacking CSQ-1 in body-wall muscles with no observable defects in locomotion. These findings suggest that although CSQ-1 is one of the major calcium-binding proteins in the body-wall muscles of C. elegans, it is not essential for body-wall muscle formation and contraction.

scholarly journals Histology and Mucous Histochemistry of the Integument and Body Wall of a Marine Polychaete Worm,Ophryotrochan. sp. (Annelida: Dorvilleidae) Associated with Steelhead Trout Cage Sites on the South Coast of Newfoundland

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
H. M. Murray ◽  
D. Gallardi ◽  
Y. S. Gidge ◽  
G. L. Sheppard
Keyword(s):  
Alcian Blue ◽  
Body Wall ◽  
Histological Study ◽  
Periodic Acid ◽  
The Body ◽  
South Coast ◽  
Steelhead Trout ◽  
The South ◽  
Periodic Acid Schiff ◽  
Marine Polychaete

Histology and mucous histochemistry of the integument and body wall of a marine polychaete worm,Ophryotrochan. sp. (Annelida: Dorvilleidae) associated with Steelhead trout cage sites on the south coast of Newfoundland. A new species of polychaete (Ophryotrochan. sp. (Annelida: Dorvilleidae)) was identified from sediment below Steelhead trout cages on the south coast of Newfoundland, Canada. The organisms were observed to produce a network of mucus in which groups of individuals would reside. Questions regarding the nature and cellular source of the mucus were addressed in this study. Samples of worms were taken from below cages and transported to the laboratory where individuals were fixed for histological study of the cuticle and associated mucus histochemistry. The body wall was organized into segments with an outer cuticle that stained strongly for acid mucopolysaccharides. The epidermis was thin and supported by loose fibrous connective tissue layers. Channels separating individual segments were lined with cells staining positive for Alcian blue. Mucoid cellular secretions appeared thick and viscous, strongly staining with Alcian blue and Periodic Acid Schiff Reagent. It was noted that lateral channels were connected via a second channel running through the anterior/posterior axis. The role of mucus secretion is discussed.

Limb regeneration in Amphiuma tridactylum (Amphibia, Urodela)

1978 ◽  
Vol 56 (11) ◽  
pp. 2327-2332 ◽  
Author(s):  
Steven R. Scadding
Keyword(s):  
Wound Healing ◽  
Body Wall ◽  
Histological Study ◽  
Limb Regeneration ◽  
Complete Loss ◽  
The Body ◽  
Limb Amputation ◽  
Slow Process

This paper reports a histological study of the response of Amphiuma to simple limb amputation. The results of simple limb amputation in this species are variable. Some limbs undergo wound healing only, others regress, resulting in complete loss of the limb except for a residual rudiment embedded in the body wall, and still others produce heteromorphic limb regenerates of size comparable with the amputated limb. Heteromorphic limb regeneration when it occurs in Amphiuma is a very slow process compared with other urodeles. After 7.5 months (longest observed specimens in this study), the process was still not complete.

Conduction and coordination in deganglionated ascidians

2000 ◽  
Vol 78 (9) ◽  
pp. 1626-1639 ◽  
Author(s):  
G O Mackie ◽  
R C Wyeth
Keyword(s):  
Body Wall ◽  
Motor Nerve ◽  
Histological Study ◽  
The Body ◽  
Nerve Terminals ◽  
Sea Anemones ◽  
Nerve Net ◽  
Electrophysiological Recordings ◽  
Motor Neurones ◽  
Conduction Of Excitation

The behaviour of Chelyosoma productum and Corella inflata (Ascidiacea) was studied in normal and deganglionated animals. Chelyosoma productum lived for over a year after deganglionation and the ganglion did not regenerate. Electrophysiological recordings were made from semi-intact preparations. Responses to stimulation and spontaneous activity continued to be transmitted through the body wall and branchial sac after deganglionation. Spread was slow, decremental, and facilitative. Treatment with >10 µg·mL-1 d-tubocurarine abolished all responses, indicating that nerves mediate conduction of excitation after deganglionation. Histological study using cholinesterase histochemistry and immunolabelling with antisera against tubulin and gonadotropin-releasing hormone showed no evidence of a peri pheral nerve net in regions showing conduction, contrary to previous claims. The cell bodies of the motor neurones were found to lie entirely within the ganglion or its major roots. Their terminal branches intermingled to form netlike arrays. Sensory neurons were identified with cell bodies in the periphery, in both the body wall and the branchial sac. Their processes also intermingled in netlike arrays before entering nerves going to the ganglion. It is concluded that the "residual" innervation that survives deganglionation is composed of either interconnected motor nerve terminals, interconnected sensory neurites, or some combination of the two. In re-inventing the nerve net, ascidians show convergent evolution with sea anemones, possibly as an adaptation to a sessile existence.

An investigation of the mechanism of infection by digenetic trematodes: the penetration of the miracidium ofFasciola hepaticainto its snail hostLymnaea truncatula

Parasitology ◽  
1971 ◽  
Vol 63 (3) ◽  
pp. 491-506 ◽  
Author(s):  
R. A. Wilson ◽  
P. Pullin ◽  
Jean Denison
Keyword(s):  
Epithelial Cells ◽  
Body Wall ◽  
Accessory Gland ◽  
The Body ◽  
Initial Attachment ◽  
Connective Tissues ◽  
Digenetic Trematodes ◽  
Ciliated Epithelial Cells ◽  
Cell Shedding

The penetration barrier presented to the miracidium by the snail epithelium can be divided into three layers. The chemical composition and physical configuration of the outermost of these plays an important part in the initial attachment response of the miracidium. Attachment can be stimulated in the absence of the snail by pure chemicals in solution. However, the surface to which the miracidium attaches must have the correct physical configuration otherwise the miracidium is unable to form a stable attachment.In vivo, the miracidial body begins to contract and relax following attachment to the snail. This coincides with the start of secretion by the apical gland and accessory gland cells. The snail's columnar epithelium is rapidly cytolysed so that 10 min after attachment the anterior of the miracidium has reached the underlying connective tissues.As the miracidium penetrates the snail, its ciliated epithelial cells are shed in sequence from anterior to posterior. This shedding removes a protective barrier against osmosis which is probably the acid mucopolysaccharide present in the epithelial cells. The mechanism of shedding is not understood but involves the reversal of binding by the desmosomal mucosubstance which attaches the epithelial cells to surrounding intercellular ridges.The miracidium metamorphoses into the sporocyst as it penetrates the snail, by forming a new body surface. The material for this is extruded from the vesiculated cells which lie beneath the musculature of the body wall. The process of surface formation coincides with cell shedding and moves backwards as cells are shed. At not more than 2·5 h after attachment the extruded cytoplasm forms a thin continuous layer over the surface of the organism. Contacts with underlying cells appear to have been broken and the cytoplasm is underlain by a thin fibrous basal lamella. In the first 24 h after penetration the surface of this syncytium becomes thrown into folds and metamorphosis into the sporocyst can be considered complete.

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.

Zinc, copper and chlorophyll-derivatives in the polychaete Owenia fusiformis

2000 ◽  
Vol 80 (2) ◽  
pp. 235-248 ◽  
Author(s):  
P.E. Gibbs ◽  
G.R. Burt ◽  
P.L. Pascoe ◽  
C.A. Llewellyn ◽  
K.P. Ryan
Keyword(s):  
High Performance ◽  
Degradation Products ◽  
The Body ◽  
Chlorophyll Degradation ◽  
Whole Body ◽  
Green Pigment ◽  
Dark Green ◽  
Light Green ◽  
Chlorophyll Derivatives

An earlier study of metals in the polychaete Owenia fusiformis showed that individuals within intertidal populations were remarkably variable in terms of whole-body concentrations of zinc and copper. Four populations have now been studied, two in south Cornwall (Fal Estuary and Par Sands) and one each in east Devon (Torre Abbey Sands) and north Brittany (Grève de St Michel). Investigations of the distributions of zinc and copper within the body have demonstrated that consistently zinc is concentrated in the middle body whilst copper increases to a maximum posteriorly. Zinc is accumulated in the mid-gut cells in the form of numerous spherules, 1–2 μm in diameter: X-ray microanalysis shows these to be largely composed of zinc phosphate but containing also magnesium, calcium and iron, together with sulphur and chlorine. Viewed under the microscope the spherules are greenish due to a pigment identified by high performance liquid chromatography absorption scanning as a pheophorbide-like chlorophyll-degradation product. In contrast, copper is widely distributed throughout the body and much is deposited as small granules, 0.2–0.3 μm in diameter, in laminar groupings in hypodermal and peri-intestinal tissues. The identity of the green pigment responsible for the characteristic body colour of O. fusiformis has not been specifically determined but it appears to have a copper basis since dark-green tissues have a significantly higher copper content than those with a light-green colour. The possible role of chlorophyll degradation products in zinc and copper uptake is discussed.

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