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PubMed1986

Common patterns of neuroendocrine integration in vertebrates and invertebrates.

Comparison between neuroendocrine integrations in vertebrates and invertebrates at the molecular (gene structure, precursor processing) and cellular (cell-cell hierarchy) levels, reveals common patterns. "Second- or third-order" hormonal cascades starting with a brain neurohormonal signal, are amplified and directed by one or two glandular relays. A parallelism may be found between the induced neurohormonal controls of reproduction. A neuroendocrine program involving several peptides could be recorded within a single gene.

Animals↗
PubMed1987

Benthic invertebrates as indicators of urban and motorway discharges.

Spatial differences in the structure and composition of the invertebrate community of a suburban river (demonstrated by the use of indices) could be explained largely in terms of organic inputs but such indices were not suitable for the detection of the low level metal contamination associated with road runoff. Analysis of plant and animal tissue proved to be a more useful strategy and significant variation in metal concentrations in several organisms could be related to the chemistry of the river water and to road and urban discharges.

Animals↗
PubMed1985

Humoral and cell membrane-associated lectins from invertebrates and lower chordates: specificity, molecular characterization and their structural relationships with putative recognition molecules from vertebrates.

Based on their carbohydrate-binding properties and their ubiquitous presence in pro- and eukaryotes, recognition functions have been hypothesized for many humoral and tissue lectins. In this review three main topics relevant to the possible biological roles and evolution of invertebrate and chordate lectins are discussed. They include the broad carbohydrate-binding spectrum of lectins from chelicerata, the distribution and specificity of cell membrane-associated lectins in mollusks and the serological and biochemical characterization of lectins from tunicates and their structural relationships with putative non-self recognition molecules from vertebrates.

Amino Acid Sequence↗
PubMed1993

Axon guidance factors in invertebrate development.

The contribution that studies in the invertebrates have made to our understanding of the factors responsible for directing axon growth is reviewed. Cellular mechanisms for axon guidance are considered, particularly the question of the accuracy of initial axon growth, and the implications of these observations for models of growth cone turning. The cellular substrates followed by growing axons during embryogenesis are identified, together with the experimental evidence that each is essential for reliable axon navigation. The significance of these studies for investigations into the molecular nature of axon guidance factors is discussed, and the likely cellular roles of putative axon guidance molecules considered.

Animals↗
PubMed1990

From cornea to retinal image in invertebrate eyes.

The optical information processing that takes place in an eye involves a large variety of very different optical components that are put together to solve a task which, in its basic nature, does not differ much from one species to another. The principal task of an eye is to sort the incoming photons so that they excite specific sensory neurons depending on angle of incidence, wavelength and plane of polarization. Despite the apparent simplicity of the task, the solutions to it are often complex and the variation between species is enormous. The pinhole camera, the Keplerian and Galilean telescopes, the corner reflector, optical fibres, and interference filters, are all names of optical devices invented by man. It now appears that all of these devices, and many more, exist in various combinations in the optics of invertebrate eyes. The similarity between man's and nature's optical engineering has been useful in many ways. For the study of eyes, it has helped to understand biological design principles in unparalleled detail.

Animals↗
PubMed1992

Motor-pattern-generating networks in invertebrates: modeling our way toward understanding.

Motor-pattern-generating networks in invertebrates have been the objects of intensive study to determine the origin and modulation of rhythmic neural activity. In some pattern generators, intrinsically bursting neurons drive activity throughout the network. In most pattern generators, however, rhythmicity arises from the interplay between intrinsic membrane properties and synaptic interaction. Reciprocal inhibitory synapses between neurons are thought to be crucial for generating oscillation in these networks, but a fundamental understanding of how such network oscillators work remains elusive. Progress towards this goal has come from attempts to combine computational modeling approaches with conventional physiological analysis.

Animals↗
PubMed1996

Signalling from neurones to glial cells in invertebrates.

Recent work shows that glial cells in species throughout the animal kingdom appear to contribute to the functioning of the neurones and are equipped to receive signals from them. However, the detailed mechanisms of the signalling and its role in vivo are generally unclear. Parts of some invertebrate nervous systems are particularly favourable for addressing these problems, and the four preparations that have been studied most intensively are the subject of this review. Between the giant axons and their Schwann glial cells in squid and crayfish, within snail brain, and in leech ganglion, there appear to be multiple, and in some cases very complex, signalling pathways, whose precise functions remain to be elucidated. In bee retina only a single signal to the glia has been demonstrated, and its function appears to be to activate transfer of metabolic substrates to the photoreceptor neurones.

Animals↗
PubMed1994

5-Hydroxytryptamine receptor subtypes in vertebrates and invertebrates.

In the last few years, molecular biology has led to the cloning and characterization of several 5-HT receptors (serotonin receptors) in vertebrates and in invertebrates. These studies have allowed identification not only of 5-HT receptors already described but also of novel subtypes. The molecular cloning of 13 different mammalian receptor subtypes revealed an unexpected heterogeneity among 5-HT receptors. Except for the 5-HT3 receptors which are ligand-gated ion channel receptors, all the other 5-HT receptors belong to the large family of receptors interacting with G proteins. Based on their amino acid sequence homology and coupling to second messengers these receptors can be divided into distinct families: the 5-HT1 family contains receptors that are negatively coupled to adenylate cyclase: the 5-HT2 family includes receptors that stimulate phospholipase C; the adenylyl cyclase stimulatory receptors are a heterogeneous group including the 5-HT4 receptor which has not yet been cloned, the Drosophila 5-HTdro1 receptor and two mammalian receptors tentatively named 5-HT6 and 5-HT7 receptors. The 5-HT5A and 5-HT5B receptors might constitute a new family of 5-HT receptors whose effectors are unknown. This review focusses on the molecular characteristics of the cloned 5-HT receptors such as their structure, their effector systems and their distribution within the central nervous system. The existence of a large number of receptors with distinct signalling properties and expression patterns might enable a single substance like 5-HT to generate simultaneously a large panel of effects in many brain structures. The availability of the genes encoding these receptors has already allowed a partial characterization of their structure-function relationship and will probably allow in the future a dissection of the contribution of each of these receptor subtypes to physiology and behaviour.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1994

Titin-related proteins in invertebrate muscles.

The localization of filaments connecting the Z-line and the A-band in insect flight muscles and the identification of very large proteins as their components is reviewed. The characterization of twitchin in the obliquely striated muscles of Caenorhabditis elegans is reported and the deductions made from its amino acid sequence are considered. The characterization of mini-titins in obliquely striated molluscan muscles is compared. The identification of projectin in the muscles of Drosophila melanogaster by anti-twitchin-antibodies, its sequence analysis and the characterization of mini-titins in arthropod and mollusc fast-striated muscles are summarized. The possible biological functions of the different proteins in various invertebrate muscles are discussed.

Animals↗
PubMedDate not supplied

The neuroimmunology of stress from invertebrates to man.

Stress can be seen as the body's most important and complex reaction to ensure survival involving the neuroendocrine systems and a variety of other organs. The investigation of the evolutionary bases of stress argues that the basic mechanisms and molecules involved in stress (CRH, ACTH, glucocorticoids, biogenic amines and cytokines) are fundamentally similar and well preserved throughout evolution in different species and taxa. A review of available data highlights that the involvement of immunity during stress response has a strong evolutionary basis and is not a mere consequence of glucocorticoid hormone release. We propose that the evolutive cellular bases of stress are to be identified in immune cells, such as invertebrate hemocytes, producing a variety of cytokine-like molecules, capable at the same time of producing a variety of hormone- and neuropeptide-like molecules and of performing a proto-stress response (release of biogenic amines). We conclude that stress, a highly conserved reaction remarkably similar in different species and taxa, is a fundamentally positive type of adaptive reaction.

Animals↗
PubMed1978

Comparative studies of vertebrate and invertebrate pyruvate kinases.

1. Electrophoretic patterns showed that among the vertebrates studied, L isozyme was present in rat and frog liver and also in rat kidney. 2. M2 is a frequent component in vertebrate tissues, giving support to the proposal that M2 is the ancestral form differentiating to other isozymes. 3. The above trend cannot simply apply to invertebrates. 4. Muscle pyruvate kinases from various animals were inhibited by the particular phosphagen present in their muscle. 5. The inhibition may have an important role in the regulation of glycolysis in muscle.

Animals↗
PubMed1985

The structure of invertebrate extracellular hemoglobins (erythrocruorins and chlorocruorins).

The knowledge accumulated over the last 30 years concerning the subunit structures of the invertebrate extracellular hemoglobins permits us to classify them into four distinct groups. Single-domain, single-subunit hemoglobins consisting of single, heme-binding polypeptide chains which have a molecular mass of ca. 16 KDa. These molecules are found in multicellular parasitic organisms such as the trematodes Dicrocoelium and Fasciolopsis and in a few insects, namely in the adult Anisops and in the larvae of Chironomus and of Buenoa. Two-domain, multi-subunit hemoglobins consisting of 30-37 KDa polypeptide chains each containing two, linearly connected heme-binding domains, which form polymeric aggregates with molecular masses ranging from 250 to 800 KDa. These hemoglobins are found extensively among the carapaced branchiopod crustaceans: Caenestheria, Daphnia and Lepidurus hemoglobins have been found to consist of 10, 16 and 24 two-domain chains, respectively. Judging from their electron microscopic appearances, some of the hemoglobins may possess different molecular symmetries. Multi-domain, multi-subunit hemoglobins consisting of two or more polypeptide chains, each comprising many heme-binding domains of ca. 15-20 KDa each. Examples of this class are found among the carapaceless branchiopod crustaceans, the planorbid snails and the clams from the families Astartidae and Carditidae. Artemia hemoglobin consists of two chains of ca. 125 KDa, each containing 8 heme-binding domains. Planorbis and Helisoma hemoglobins possess a molecular mass of ca. 1700 KDa and consist of 10 chains of 170-200 KDa. Astarte and Cardita hemoglobins appear in electron micrographs as rod-like polymers of variable dimensions, 20-30 nm in diameter and 20-100 nm in length and consist of polypeptide chains of ca. 300 KDa. The crustacean and gastropod hemoglobins vary in their electron microscopic appearance and may possess different molecular symmetries. Single-domain, multi-subunit hemoglobins consisting of aggregates of several small subunits, some of which are disulfide-bonded and not all of which contain heme. These molecules are widely distributed among the annelids and possibly also among the pogonophores. They are characterized by a two-tiered, hexagonal electron microscopic appearance, with a vertex-to-vertex diameter of 30 nm and a height of 20 nm, an acidic isoelectric point, a sedimentation coefficient of 50-60 S and a low iron content of 0.24 +/- 0.03%.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1987

Activities of adenylate-degrading enzymes in muscles from vertebrates and invertebrates.

Activities of adenylate-degrading enzymes in muscles of vertebrates and invertebrates were determined. Mammalian and fish muscles showed a markedly higher activity of AMP deaminase with a lower level of adenosine deaminase and 5'-nucleotidase. Cephalopods showed an active adenosine deaminase and a 5'-nucleotidase which preferred AMP as the substrate. Negligible deamination of AMP and adenosine and little phosphohydrolase activity toward AMP and IMP were observed in the shellfish muscles. Adenine nucleotides can be degraded to form IMP via the AMP deaminase reaction in vertebrate muscles, while dephosphorylation of AMP to adenosine, which is then converted to inosine, appears to proceed in cephalopods. Adenylates can be hardly degraded in shellfish muscles.

5'-Nucleotidase↗
PubMed1987

Ubiquitous presence of calciferin-like and cathepsin D-like activities in the sera (vertebrates) and humoral fluids (invertebrates).

1. Sera (or humoral fluids) from various animals (vertebrates and invertebrates) were assayed for calciferin-like and cathepsin D-like activities, indicating the ubiquitous presence of the latter and the former (with a few exceptions). Animals other than the mammals appeared to contain an organophilic calciferin-like activity in addition to a hydrophilic component (calciferin). 2. A correlation was found between the levels of calciferin and acid protease in most of the mammalian sera. An age-dependent decrease in calciferin (but not acid protease) was found in human sera. The possible presence of an acid protease-inhibitor was suggested.

Animals↗
PubMed1988

Collagen cross-linking: distribution of hydroxypyridinium cross-links among invertebrate phyla and tissues.

1. Using a specific HPLC assay, a wide variety of marine invertebrate connective tissues was screened for the 3-hydroxypyridinium amino acids that are prominent intermolecular cross-linking residues in the collagens of many vertebrate connective tissues. 2. One or both of the two structural forms that exist, hydroxylysyl pyridinoline (HP) and lysyl pyridinoline (LP), was found in organisms from the following phyla: coelenterata, Annelida, Echinodermata, Mollusca and Arthropoda. 3. Neither amino acid was found in tissues from representative species of Porifera and Chordata. 4. Of special note was an unusually high ratio of LP to HP in Limulus polyphemus gill cartilage.

Animals↗
PubMed1990

Pyruvate kinase isoenzymes in marine invertebrates: a comparative study by the use of monoclonal antibodies.

1. Six monoclonal antibodies specific to the pyruvate kinase from the foot muscle of the common limpet P. caerulea were produced. 2. They also exhibited specificity against the mouse liver where the L-type isoenzyme of pyruvate kinase is present. They did not react with the mouse skeletal muscle, heart or red blood cells isoenzymes of pyruvate kinase (PK). One of these, the monoclonal antibody B did not react with any PK isoenzymes of the mouse tissues. 3. The presence of the isoenzymic type of PK which was recognized by the monoclonals, (type L), was traced in five phyla of marine invertebrates by the application of the monoclonal antibodies A, B and C. 4. In two phyla the majority of the animals were found to possess an L-type PK isoenzyme in their muscles while in quite a few of them a different isoenzymic type was present in the other tissues. The results of this study are compared with the existing literature, and the use of monoclonal antibodies in the study of enzymic systems is considered in the discussion.

Animals↗
PubMed1992

The search for effectors of beta-D-glucanases among marine invertebrates.

1. The search for inhibitors and activators of endo-1----3-(EC 3.2.1.6) and 1----6-beta-D-glucanases (EC3.2.1) from marine mollusks in aqueous and ethanol extracts of various types of marine invertebrates, such as sponges, ascidians, coelenterates, echinoderms, dwelling in north seas (the sea of Okhotsk and the sea of Japan) and torrid seas (western coast of Australia) has been made. 2. A comparative analysis has shown that the overwhelming majority of extracts of animals, dwelling near Australia, inhibit beta-D-glucanases. 3. On the contrary, the extracts of animals dwelling in the sea of Okhotsk possess the activating effect, except for sponges of genera Haliclona whose sample extracts display a significant activating effect independently of their place of abode.

Animals↗
PubMed1996

High-performance liquid chromatographic determination of the imino acids (opines) meso-alanopine and D-strombine in muscle extract of invertebrates.

A sensitive HPLC method is presented for the determination of the imino acids alanopine and strombine, anaerobic metabolites that are formed in muscle tissue of several species of invertebrates. The separation of alanopine and strombine was achieved using the Alltech OA 2000 cation-exchange column. The analysis of the two opines does not require any complicated derivatization and can be performed in a pH neutralized sulphuric acid solution. The sensitivity of this method is in the range of 100 pmol to at least 10 nmol for both investigated opines. For the first time opines were demonstrated in the bivalves Macoma balthica and Cerastoderma edule.

Alanine↗