Research on polychaete annelid osmoregulatory peptide(s) by immunocytochemical and physiological approaches. Computer reconstruction of the brain and evidence for a role of angiotensin-like molecules in Nereis (Hediste) diversicolor OF Müller.

Immunohistochemical and physiological studies were carried out on Nereis (Hediste) diversicolor OF Müller in order to obtain evidence concerning the neuroendocrine control of polychaete osmoregulation. The occurrence in this animal of peptides immunologically related to mammalian angiotensin II and I (AII and AI) and oxytocin (OT) was demonstrated in the brain and the ventral nerve cord (VNC) perikarya and nerve fibres as well as in a few peripheral structures (peripheral nerves, epithelial cells, nuchal organ, intestine and nephridia). The exact localization of immunoreactive cells was achieved by serial sections of brain and ventral nerve cord followed by a three-dimensional reconstruction of brain ganglionic nuclei using the CATIA ('Conception Assistée Tridimensionnelle Inter Active') Dassault system program.

Amino acid sequence of the small cadmium-binding protein (MP II) from Nereis diversicolor (annelida, polychaeta). Evidence for a myohemerythrin structure.

The primary sequence of the low-molecular-mass cadmium-binding protein metalloprotein II of Nereis diversicolor (Hediste diversicolor, recent denomination) has been determined. This protein is composed of 119 amino acids and has 80.8% identity with the N.

Some polypeptides in the nervous system of the marine worm, Nereis diversicolor, are related to the sodium influx stimulating peptide of the pulmonate freshwater snail, Lymnaea stagnalis.

Total mRNA, extracted from brain of the marine worm, Nereis diversicolor (Annelida, Polychaeta), was translated either in vitro using a rabbit reticulocyte lysate or in ovo (Xenopus laevis oocyte). The synthesized polypeptides were analyzed by electrophoresis and Western blotting techniques using polyclonal antisera raised against three peptides: sodium influx stimulating peptide (SISP) sequences 10-19 and 67-76 and a monoclonal antibody raised against purified native SISP (1-77) of Lymnaea stagnalis. Among the products translated in vitro, three polypeptides of 80, 72, and 64 kDa were recognized by the anti-SISP (10-19) polyclonal antiserum and by the monoclonal antiserum, but not by anti-SISP (67-76).

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.

Isolation and characterization of authentic Phe-Met-Arg-Phe-NH2 and the novel Phe-Thr-Arg-Phe-NH2 peptide from Nereis diversicolor.

Immunocytochemical studies have shown that peptides like Phe-Met-Arg-Phe-NH2 (FMRFamide) are widely distributed throughout the nervous system of three Nereidae. In Nereis diversicolor we have isolated these peptides from an extract of total worms by affinity chromatography and two steps of reversed-phase high-performance liquid chromatography. The sequences of the purified peptides have been determined by amino acid sequencing and on the basis of their reactivity with an anti-FMRFamide serum specific for the determinant Arg-Phe-NH2.

Precursors of neuropeptides in the marine worm Nereis diversicolor. In vitro translation of a precursor related to human prepro-cholecystokinin and immunolocalization of this precursor in the nervous system.

Total mRNA extracted from the brain of a marine worm, Nereis diversicolor, were in vitro translated using 2 cell-free systems: rabbit reticulocyte lysate and wheat germ extract. Among numerous products newly translated in both systems, only one class of 70 kDa polypeptides immunoprecipitated when we used a mixture of 3 well defined antibodies raised against known sequences of the human prepro-CCK. At the cellular level, using immunocytochemistry techniques, strong and moderate immunoreactivities were seen in perikarya located in various ganglionic nuclei of the worm brain.

[Homologies between hemerythrins of sipunculids and cadmium-binding metalloprotein (MP II) from a polychaete annelid, Nereis diversicolor].

The determination of the first 33 amino acids of the Cd-binding-protein (MP II) of Nereis diversicolor (Annelida, Polychaeta) shows a homology of 79 and 61% with 2 respiratory proteins of sipunculids, respectively the myohemerythrin and the hemerythrin. The positive reaction obtained by immunocytochemistry over the hemerythrocytes of Sipunculus nudus using antibodies raised against MP II and the presence of iron on the MP II reinforce this similarity.

Translation in a cell-free system, and in Xenopus oocytes, of mRNA which specify a cadmium-binding protein in Nereis diversicolor (Annelida, Polychaeta).

The presence in the marine worm Nereis diversicolor of a low molecular mass protein with the capacity to bind cadmium has been previously demonstrated. Poly(A)(+)-mRNA were extracted from coelomocytes of Nereis diversicolor and were translated either in vitro, using a rabbit reticulocyte lysate, or in vivo into Xenopus laevis oocytes. Analysis of synthesized polypeptides by enzyme-linked immunosorbent assay (ELISA) and by Western blotting, using a specific monoclonal anti-MP II antibody, showed that this metalloprotein was translated both in in vitro and in vivo translation systems, with an apparent molecular mass of 11-13 kDa.

A qualitative approach of the Nereis neuropeptides by use of antibodies to several vertebrate peptides.

Comparison of the localization of immunoreactivities which were obtained with antibodies to ?-endorphin, ?-neoendorphin, Leu- and met-enk and dynorphin with those obtained earlier using antisera to ?-endorphin, somatostatin, CRF, GRF, ?-MSH, CCK/gastrin, VIP and substance P (Dhainaut-Courtois et al., 1985a,b) show the particular status of opiate-like substances in Nereis. Indeed, immunoreactivities for vertebrate opiates were observed quite exclusively in the brain, on paraffin embedded as well as on frozen tissue sections.

Occurrence and coexistence in Nereis diversicolor O.F. Müller (Annelida Polychaeta) of substances immunologically related to vertebrate neuropeptides.

Numerous immunochemical and immunohistochemical studies have shown a wide distribution of several families of neuropeptides in invertebrates as well as vertebrates. There are relatively few data available for Annelida: Polychaeta. Therefore, we undertook an immunohistochemical investigation in the marine worm Nereis.

Immunohistochemical demonstration of a CCK-like peptide in the nervous system of a marine annelid worm, Nereis diversicolor O.F. Müller.

Perikarya and nerve fibers containing a substance immunologically related to CCK-8 were detected in the nervous system of Nereis, a marine annelid worm. The most noteworthy immunostaining was seen in cell bodies, localized at the periphery of the brain, within nuclei 5, 6, 7, 9, 10, 13, 14, 15, 17, 20, 23-24. Immunoreactive fibers were also found in the neuropile without any particular grouping.

[Aminergic neurosecretions in invertebrates].

This minireview of aminergic neurosecretions of invertebrates deals with technics of detection and localization of these substances and considers their mode of action at cellular or organ level. A comparison with vertebrates is given. Some examples are analyzed as models.

[Contribution to the study of nervous system in larval and adult forms of Schistosoma mansoni Sambon, 1907 (Trematoda Digenea). II. Role of serotonine and dopamine (author's transl)].

This study provides details concerning the localization and role of 5-HT and DA in Schistosoma: 1) 3H-5HT is incorporated selectively by the nerve fibers containing dense granules measuring 820 +/- 20 A (type 2 granules), combined at times with other structures; the presence of "cold" dopamine in the environment does not alter the incorporation; 2) 3H-DA is also incorporated in vitro by the nerve fibers and occasionally by the muscle fibers of the adult Schistosoma; 3) neither the intraovular miracidium, the first and second generation sporocystes, nor the intrasporocystic cercariae appear to incorporate the 3H-5-HT or the 3H-DA, under our working conditions. The two amines are, however, incorporated by the hepatopancreas of Biomphalaria glabrata and the 3H-5-HT produced marking on certain neuromuscular zones of the tentacle.

[Light and electron microscopic localization of cholinesterase activity in a marine invertebrate (Nereis pelagica L., Annelida, Polychaeta)].

High specific and nonspecific cholinesterase activities have been demonstrated in the whole nervous system of Nereis. These might reveal the existence of a cholinergic nervous system whose control would be exerted in different sites (central nervous centers, muscular junctions..