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At least 235 records · Page 13Linked to original sources
PubMed1981

Uptake of tritium-labelled biogenic amines by the prostomium of the polychaete Nereis virens (Sars) (Annelida).

The uptake of tritium-labelled 5-HT, noradrenaline, 5-hydroxytrytophan, DOPA and dopamine by the cerebral ganglion and prostomial nervous system of the polychaete Nereis virens has been examined using radioautography at the level of the light microscope. Pronounced uptake of (3)H-5HT occurred in the antennal, palpal, tegumentary and nuchal nerves as well as in ganglionic nuclei 13, 14, 15, 16, 17, 20, 24 and 25, the mid-brain neuropile, the neurosecretory neuropil and the infracerebral organ; (3)H-NA uptake was observed in small cells in the prostomial epidermis, and the infracerebral organ; (3)H-dopamine only in one of two common types of epidermal mucus cells. Prostomial muscles labelled generally with (3)H-NA and at specific sites with (3)H-5HT. These observations support the concept of an efferent serotonergic system originating in several cerebral ganglionic nuclei and serving prostomial muscle and epidermis. Evidence for an afferent adrenergic system is less substantial. The role of dopamine remains obscure.

5-Hydroxytryptophan↗
PubMed1987

Comparative analysis of hemolytic and hemagglutinating activities in the coelomic fluid of Eisenia foetida and Lumbricus terrestris (Annelida, Lumbricidae).

The CF of Lumbricus terrestris and Eisenia foetida was analyzed with regard to the protein patterns by isoelectric focusing. The CF of E. foetida results in a variety of protein bands; after separation: seven of these with isoelectric points at pH 5.1, 5.2, 5.4, 5.6, 5.8, 6.0 and 6.2 cause the hemolysis of red blood cells. The protein pattern of normal CF of L. terrestris is relatively poor. Most of the protein bands are located at the top of the separation (pH less than 5.1) near the anode. However, the number of protein bands is drastically enhanced within 24 hours after an intracoelomic injection of foreign material. Some of the induced proteins show a similar pattern at comparable pH ranges to the CF of E. foetida. The induced proteins with isoelectric points at pH 4.7, 5.0, 5.1, 5.2, 5.4, 5.8, 6.0 and 6.2 effect the hemolysis of vertebrate erythrocytes. After stimulation with rabbit erythrocytes an enhanced bactericidal and bacteriostatic activity against Proteus vulgaris can be proven and seems to be related to the induced hemolytic proteins. The antibacterial activity can be completely adsorbed by incubation of the CF with rabbit erythrocytes, which indicates its binding ability to marker molecules on the erythrocytes surface.

Animals↗
PubMed1988

Distribution and nature of membrane receptors for different plant lectins in the coelomocyte subpopulations of the Annelida Nereis diversicolor.

Studies on membrane receptors have been performed on the Nereis coelomocytes using various lectins. In the agglutination assay, only LCA and WGA appeared nonreactive. Fluorescent lectins showed the poor reactivity of the eleocytes and the diversity of the receptors according to the granulocyte types. Types I-granulocytes reacted only with Con A. Type II-granulocyte membrane contained mannose and galactose receptors (reactivity with Con A, PNA and SBA). The type III-granulocyte membrane revealed the presence of mannose and fucose receptors (UEA, AAA). Electron microscope investigations with HRP-DAB or mannosyl labelled Con A, RCAI and LTA have confirmed the distribution of the membrane receptors.

Animals↗
PubMed1991

Detection of antigen in the coelomocytes of the earthworm, Eisenia foetida (Annelida).

Earthworms, Eisenia foetida, are able to respond to antigenic stimulation by the formation of the antigen-binding molecules by coelomocytes--the effector cells of annelids' defence reactions. The ability to react with gold-labelled antigen was detected in agranular coelomocytes by electron microscopy. Furthermore, flow cytometry analysis used for quantitative evaluation of antigen binding showed significant increase of both antigen-binding cells and the amount of antigen bound per cell after stimulation. The antigen binding was inhibited by preincubation of cells with several similar proteins, although the most potent inhibitor was the immunizing antigen.

Animals↗
PubMed1996

Crossreactivity of hemolytic and hemagglutinating proteins in the coelomic fluid of lumbricidae (Annelida).

Oligospecific antisera against the hemolytic and hemagglutinating compounds of the coelomic fluid (CF) of the earthworm species Eisenia fetida, Lumbricus terrestris and Aporrectodea caliginosa were prepared. The proteins were bound to the membranes of erythrocytes and injected into rabbits. By the use of these antisera the following results were obtained: 1) The antisera RaL T and RaAC reached a titer of 1:64,000, the detection limit of RaEF was 1:512,000. RaEF was demonstrated to be oligospecific only against three hemolytic proteins by Western blotting. 2) RaEF is able to inhibit the biological activity not only of hemolysins (E. fetida, A. caliginosa) but also of hemagglutinins (L. terrestris, L. rubellus, D. rubidus). 3) Complex carbohydrates, but not simple sugar compounds, are able to inhibit hemolytic and agglutinating activities in the CF of the investigated species. Fet. and alpha 1ac. GP were demonstrated to be strong inhibitors both of the hemolytic and of the hemagglutinating activity, whereas N-acetylglucosamine was only able to inhibit the hemagglutinating activity. 4) The investigated compounds were shown to crossreact in ELISA experiments. 5) By the use of Western blotting, the crossreacting molecules in the CF of the investigated lumbricid species were identified.

Animals↗
PubMed1986

Isolation of polypeptide chains with heme from the extracellular hemoglobin of Amphitrite ornata (Polychaeta, Annelida).

From the extracellular hemoglobin of Amphitrite ornata four constituent polypeptide chains containing heme and designated AI, AII, BI and BII according to the elution order were obtained by DE52-cellulose ion-exchange chromatography with dithiothreitol (DTT) as a reducing reagent. The NH2-terminal sequences for the chains are AI, Asp-Ser-Asn-Ala; AII, Glu-Tyr-Thr; BI, Asp-Phe-Asn-Thr; and BII, Asp-Ser-Glu. Each of the isolated chains showed spectra similar to those of vertebrate hemoglobins, and they bound oxygen reversibly. Acid urea polyacrylamide gel electrophoresis separated four bands, corresponding to the isolated chain, from the intact extracellular hemoglobin reduced with DTT. These results and our failure to detect an appreciable amount of non-heme protein suggest that the extracellular hemoglobin of A. ornata is composed of four polypeptide chains, each containing a heme.

Animals↗
PubMed1992

Isolation and characterization of a Cd-binding protein from Allolobophora caliginosa (Annelida, Oligochaeta): distinction from metallothioneins.

1. One Cd-binding peak was detected after gel filtration chromatography on Sephadex G75 in an extract from Allolobophora caliginosa contaminated with Cd. 2. Two subsequent cation-exchange chromatographies allowed the isolation of a Cd-binding protein which was called Cd-BP14. This protein is a monomer with a molecular weight of 14 kDa and has an isoelectric point of 6.5. 3. Amino acid analysis showed the presence of a high level of aromatic amino acids and a lack of cysteine. 4. On the basis of these results we conclude that Cd-BP14 is different from metallothioneins described in mammals or other invertebrates.

Amino Acids↗
PubMed2004

The multifunctional role of fibroblasts during wound healing in Hirudo medicinalis (Annelida, Hirudinea).

Extracellular matrix components play a key role during the angiogenic process for a correct development of blood vessels: fibroblasts are the main cell type involved in the regulation of ECM protein production. In this study we characterize H. medicinalis fibroblasts and demonstrate that they take part to the regulation of angiogenesis that occurs during wound healing process. Massive proliferation and phenotypic modification are two distinctive markers of fibroblast activation. These cells, that are usually responsible for collagen production and function as an energy reservoir, are recruited during wound healing to form a collagen scaffold through a direct mechanic action and through secretion of specific proteoglycans. In addition we show that the activity of fibroblasts is modulated by EGF, a growth factor involved in wound healing in vertebrates. The formation of bundles of collagen fibrils by fibroblasts is fundamental for the development and migration of new blood vessels in lesioned areas during wound repair: administration of lovastatin in explanted leeches affects fibroblasts, damages collagen "scaffold" and indirectly causes the reduction of neo-capillary formation.

Animals↗
PubMed2005

Regulation of vitellogenesis in Nereis virens (Annelida: Polychaeta): effect of estradiol-17beta on eleocytes.

In the marine polychaete Nereis virens, the yolk protein precursor vitellogenin (Vg) is synthesized in specialized coelomic cells (eleocytes) during oogenesis. This process was visualized by immunohistochemistry using antibodies raised against the yolk protein. Transversal sections from male and female worms confirmed that eleocytes from females but not from males produce Vg. In order to investigate the hormonal regulation of Vg synthesis, eleocytes were incubated in vitro with estradiol-17beta (E(2)) at a concentration of 1 microg/l for up to three days. A strong increase in Vg secretion was detected by ELISA in culture media of treated eleocytes from vitellogenic females. In contrast, no response to the hormonal treatment was detectable in immature worms. Our results showed that Vg synthesis is under a complex regulation, which involves endocrine factors like estrogens. The role of E(2) in vitellogenesis of N. virens rather resembles the situation found in vertebrate than the one in insects.

Animals↗
PubMed2004

Identification of two Nereis virens (Annelida: Polychaeta) cytochromes P450 and induction by xenobiotics.

Cytochrome P450 (CYP) enzyme catalysed metabolism of xenobiotics such as polycyclic aromatic hydrocarbons (PAHs) are known to occur in polychaetes. Yet specific polychaete CYP enzymes have so far not been identified. Here, we report two partial CYP cDNA sequences, both of 453 bp, characterised from Nereis virens. These are the first CYP sequences reported in annelids. The deduced amino acid sequences both share highest identities to mammalian CYP4F enzymes (61% and 58%), indicating membership of the CYP4 family (accordingly, referred to as CYP41 and CYP42, respectively). The CYP42 gene expression was significantly higher in vehicle controls (corn oil) compared to untreated controls. Clofibrate increased the expression of the CYP42 genes. The induction by clofibrate and corn oil indicates regulatory similarities to vertebrate CYP4 enzymes, which are primarily involved in the metabolism of endogenous compounds such as fatty acids. Crude oil and benz(a)anthracene significantly induced CYP42 gene expression 2.6-fold, and because CYP enzymes often are induced by their own substrates, this induction may indicate involvement of N. virens CYP4 enzymes in the detoxification of environmental contaminants such as PAHs. The present study demonstrates that these N. virens CYP genes are transcriptionally inducible, and suggests that N. virens CYP4 enzymes may be involved in the metabolism of both exogenous and endogenous compounds.

Amino Acid Sequence↗
PubMed2006

Bacterial accumulation by Branchiomma luctuosum (Annelida: Polychaeta): a tool for biomonitoring marine systems and restoring polluted waters.

In this study, we examined the bacterial accumulation in the filter feeder polychaete Branchiomma luctuosumGrube (Sabellidae). Analyses were performed on worm homogenates from 'unstarved' and 'starved' individuals, and seawater from the same sampling site (Gulf of Taranto, Western Mediterranean, Italy). Densities of culturable heterotrophic bacteria (22 degrees C), total culturable bacteria at 37 degrees C and halophilic vibrios at 22 and 35 degrees C were measured on Marine Agar 2216, Plate Count Agar and thiosulphate-citrate-bile-salt-agar (TCBS) plus 2% NaCl, respectively. Total and faecal coliforms as well as faecal streptococci were determined by the Most Probable Number method. Results showed that B. luctuosum is able to accumulate all the considered six microbiological groups with a higher efficiency for autochthonous bacteria. The analysis also indicated that bacterial groups differ in their resistance to digestion by B. luctuosum. Our data suggest the potential role of B. luctuosum as an useful bioindicator to assess low levels of microbiological water pollution as well as bioremediator of microbial polluted waters.

Animals↗
PubMed2004

Ultrastructural properties of the Theromyzon (Annelida: Hirudinae) cocoon membrane.

The cocoon of the leech Theromyzon trizonare consists of fibrils packed into an arrangement that produces both C- and S-like patterns of bow-shaped lines in sections oblique through the membrane. Sections normal to the cocoon membrane show layers containing cross-sections of fibrils (approximately 16 nm dia.) that are separated by a center-to-center distance of approximately 23 nm. In cross-section, each fibril presents a central hole approximately 5 nm in diameter. A structureless layer covers most of the exterior surface of the cocoon membrane, and short protuberances are apparent in some zones.

Animals↗
PubMed2006

Oogenesis in the leech Glossiphonia heteroclita (Annelida, Hirudinea, Glossiphoniidae) II. Vitellogenesis, follicle cell structure and egg shell formation.

By the end of previtellogenesis, the oocytes of Glossiphonia heteroclita gradually protrude into the ovary cavity. As a result they lose contact with the ovary cord (which begins to degenerate) and float freely within the hemocoelomic fluid. The oocyte's ooplasm is rich in numerous well-developed Golgi complexes showing high secretory activity, normal and transforming mitochondria, cisternae of rER and vast amounts of ribosomes. The transforming mitochondria become small lipid droplets as vitellogenesis progresses. The oolemma forms microvilli, numerous coated pits and vesicles occur at the base of the microvilli, and the first yolk spheres appear in the peripheral ooplasm. A mixed mechanism of vitellogenesis is suggested. The eggs are covered by a thin vitelline envelope with microvilli projecting through it. The envelope is formed by the oocyte. The vitelline envelope is produced by exocytosis of vesicles containing two kinds of material, one of which is electron-dense and seems not to participate in envelope formation. The cortical ooplasm of fully grown oocytes contains many cytoskeletal elements (F-actin) and numerous membrane-bound vesicles filled with stratified content. Those vesicles probably are cortical granules. The follicle cells surrounding growing oocytes have the following features: (1) they do not lie on a basal lamina; (2) their plasma membrane folds deeply, forming invaginations which eventually seem to form channels throughout their cytoplasm; (3) the plasma membrane facing the ovary lumen is lined with a layer of dense material; and (4) the plasma membrane facing the oocyte forms thin projections which intermingle with the oocyte microvilli. In late oogenesis, the follicle cells detach from the oocytes and degenerate in the ovary lumen.

Animals↗
PubMed2004

Arhynchobdellida (Annelida: Oligochaeta: Hirudinida): phylogenetic relationships and evolution.

A remarkable diversity of life history strategies, geographic distributions, and morphological characters provide a rich substrate for investigating the evolutionary relationships of arhynchobdellid leeches. The phylogenetic relationships, using parsimony analysis, of the order Arhynchobdellida were investigated using nuclear 18S and 28S rDNA, mitochondrial 12S rDNA, and cytochrome c oxidase subunit I sequence data, as well as 24 morphological characters. Thirty-nine arhynchobdellid species were selected to represent the seven currently recognized families. Sixteen rhynchobdellid leeches from the families Glossiphoniidae and Piscicolidae were included as outgroup taxa. Analysis of all available data resolved a single most-parsimonious tree. The cladogram conflicted with most of the traditional classification schemes of the Arhynchobdellida. Monophyly of the Erpobdelliformes and Hirudiniformes was supported, whereas the families Haemadipsidae, Haemopidae, and Hirudinidae, as well as the genera Hirudo or Aliolimnatis, were found not to be monophyletic. The results provide insight on the phylogenetic positions for the taxonomically problematic families Americobdellidae and Cylicobdellidae, the genera Semiscolex, Patagoniobdella, and Mesobdella, as well as genera traditionally classified under Hirudinidae. The evolution of dietary and habitat preferences is examined.

Animals↗
PubMed2004

A cysteine-rich protein in the Theromyzon (Annelida: Hirudinea) cocoon membrane.

The aquatic leech, Theromyzon rude, secretes a flexible, proteinaceous cocoon that is resistant to a broad range of denaturing conditions (e.g. heat, denaturing chemicals). We have partially solubilized the Theromyzon cocoon membrane in 10% acetic acid and identified two major protein fragments. Microsequencing of both Theromyzon cocoon protein (Tcp) fragments generated an identical stretch of the amino-terminal sequence that was used to clone the corresponding gene. The predicted linear amino acid sequence of the resulting cDNA contained an unusually high cysteine content (17.8%). Sequence analysis identified six internal repeats, each comprising 12 ordered Cys residues in a approximately 62 amino acid repeating unit. Sequence comparisons identified homology with undescribed, Cys-rich repeats across animal phyla (i.e. Arthropod, Nematoda).

Amino Acid Sequence↗