Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Invertebrates”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,117 records · Page 62Linked to original sources
PubMed2005

[Estimating the gene pool condition in natural populations of invertebrates in the fragmented landscape of Moscow and Moscow district with special reference to shrub snail Bradybaena fruticum Müll].

Using shrub snail Bradybaena fruticum Müll (20 populations) as a model, we were the first in Russia and in the world to develop a system of urban ecological genetic monitoring of the gene pool of an invertebrate species. The results of isozyme polymorphism studies in shrub snail populations showed a dramatic (up to 70%) reduction in genetic diversity in small isolates from the urbanized environment as compared to large natural populations. In urban populations, genetic diversity parameters were demonstrated to be lower than in natural ones: the mean heterozygosity per locus was reduced up to 0.08 (0.15-0.20 in natural populations); the mean allele number, to 1.9 (2.7 in natural populations); and the number of polymorphic loci, to four, i.e., 2.2-fold (nine in natural populations). In Moscow district, the number of polymorphic loci also decreased to five in the population subjected to anthropogenic pressure. The changes in the population gene pool (as shown by the number of polymorphic loci) were different in Moscow and Moscow district. The percentage of populations with the number of polymorphic loci as low as four to six was 76.9 in Moscow and 23.1% in Moscow district. The gene pool quality of 80% of the urban snail populations was estimated as unsatisfactory, and in half of them, as critical. The main reason for these changes seems to be genetic drift accompanied by inbreeding, caused by fragmentation of the range and reduction in the abundance of populations of the species, due to the anthropogenic pressure. The results of the study were employed in the program of the Moscow government for restoring the gene pools of endangered animals species on the preserved territories of the city.

Animals↗
PubMed1991

Cytology of pollutant metals in marine invertebrates: a review of microanalytical applications.

X-ray microanalysis (XRMA) is customized for investigations of the metabolic and detoxification strategies of heavy metals taken by marine organisms from polluted environments. Sites of uptake, intracellular accumulation, transport and excretion are visualized, analysed and quantified. Cryopreparation techniques are required to prevent the translocation or loss from specimens of soluble metal species. In marine invertebrates, metals are detoxified by systems of chemical binding and intracellular compartmentalization. XRMA investigations have concentrated on marine molluscs and crustaceans and even within these restricted groups there are marked inter-species differences in the biochemical and cytological processes which reduce metal bioavailability. Some detoxification systems also protect the carnivores which ingest the metal-laden tissues of the prey. This results in the bioreduction of metals along a food chain. These processes are investigated by XRMA which can be tuned to observe the complex interactions which operate at all levels within and between the biota and polluted environments.

Animals↗
PubMed1988

Expression of human tyrosine hydroxylase cDNA in invertebrate cells using a baculovirus vector.

A human cDNA containing the complete coding sequence for a human tyrosine hydroxylase (EC 1.14.16.2, form 2) was introduced into the genome of Autographa californica nuclear polyhedrosis virus (AcNPV) downstream to the polyhedrin promoter. Infection of Spodoptera frugiperda cells (SF9) with recombinant virus resulted in the expression of human tyrosine hydroxylase in these invertebrate cells. Characterization of tyrosine hydroxylase activity in infected SF9 cells demonstrated both substrate and cofactor kinetics that were characteristic of those previously reported for the native human enzyme. Both 3-iodotyrosine and alpha-methyl-p-tyrosine competitively inhibited the recombinantly produced tyrosine hydroxylase with Ki values of 1.2 and 16 microM, respectively, similar to those previously reported for the rat and human enzymes. Western blot analysis of extracts of SF9 cells infected with the recombinant baculovirus containing human tyrosine hydroxylase cDNA revealed a major immunoreactive band with an apparent Mr of 60 kDa, identical to the size of the immunoreactive protein from rat adrenal and caudate nucleus. The use of the baculovirus expression system to produce abundant quantities of each of the multiple forms of active human tyrosine hydroxylase in eukaryotic cells should facilitate structural analysis and help clarify the physiological significance of each of the isoenzymes.

Base Sequence↗
PubMed1977

Tridacnin, a new mitogenic lectin from invertebrate sources.

A new group of invertebrate lectins with anti-beta-galactosyl specificity, the so-called Tridacnins from the Tridacnid bivalve clams have been found to show not only agglutinating and precipitating properties, but also mitogenic activity as tested with human lymphocytes.

B-Lymphocytes↗
PubMed1985

Physiological adaptations and the concepts of optimal reproductive strategy and physiological constraint in marine invertebrates.

The dominant 'demographic' theory of life history evolution supposes that different lifetime patterns of reproduction are the result of selection of alternative optimal solutions for the allocation of limited resources between somatic and reproductive functions. A number of trade-off possibilities have been recognized--those between current reproductive output and residual reproductive value and between fecundity and initial offspring size being considered especially important. Many theoretical studies assume that natural selection will favour the adoption of optimal solutions, but it has been pointed out that such solutions may not be obtainable due to design constraints and the development of physiological adaptations to specific reproductive traits which limit subsequent evolutionary potential. The validity of this idea is examined in this paper through a review of the major reproductive strategies available to marine invertebrates and the physiological adaptations associated with them. The ecologically important distinction between planktotrophic and lecithotrophic development is not necessarily associated with major physiological adaptations in the adults, but the distinction between strictly semelparous and iteroparous life histories is. This is demonstrated in a survey of the endocrinological and environmental control of reproductive processes in related organisms with contrasting modes or reproduction. Particular reference is made to the Polychaeta, in which the contrast between semelparous and iteroparous life histories is particularly marked. A similar contrast is found between cephalopoda and other mollusca, and the discussion of physiological adaptations is extended to include these groups and the Echinodermata.

Adaptation, Physiological↗
PubMed1985

Metabolic adaptations of intertidal invertebrates to environmental hypoxia (a comparison of environmental anoxia to exercise anoxia).

By comparing environmental anaerobiosis with exercise anaerobiosis it appears that animals with high anoxia tolerance use (partly) different types of metabolic reactions to sustain energy metabolism, whereas low tolerance animals (Arthropoda, Echinodermata, Vertebrata) use the same pathway under both conditions. During exercise anaerobiosis the classical glycolysis (lactate pathway) is a main pathway among all multicellular organisms, although in marine invertebrates--except the Arthropoda and Echinodermata--it mostly does not terminate in lactate. During environmental anaerobiosis Cnidaria, Mollusca, Annelida and Sipunculida first couple additional pathways for energy extraction to the glycolytic pathway (the aspartate--succinate pathway) and later deviate the main carbon flow of glycogen at the level of phosphoenolpyruvate towards succinate, propionate and acetate production. Metabolic adaptations to anoxic cellular conditions in these groups are high fuel stores, increased ATP yield by anaerobic sources, formation of easily excretable (volatile) end products, an aspartate-dependent system for transport of hydrogen through the inner membrane of the mitochondrion and a rapid recovery from anaerobic metabolism. During anaerobic conditions three sources can contribute to the anaerobic power output, endogenous stores of both ATP and phosphagen and catabolism. Anaerobic power output rates have been calculated for a number of Mollusca, Annelida and Crustacea. Extreme anoxia resistance is coupled to a strongly reduced metabolic rate. In animals with high aspartate stores, the aspartate--succinate pathway and phosphagen hydrolysis can provide sufficient ATP during environmental anaerobiosis; however, with exercise anaerobiosis when ATP turnover rates may be increased by a factor of 20, pyruvate derivatives simultaneously accumulate in high amounts relative to succinate.

Adaptation, Physiological↗
PubMed1985

[Effect of invertebrate rickettsiae on vertebrates: experimental infection of mice by Rickettsiella grylli].

An analysis by cytology, electron microscopy, and serology of experimental infections of the mouse by an invertebrate rickettsia with chlamydial cycle, Rickettsiella grylli, showed that, according to the routes and the severity of the infection, the pathogen can have no effect, or cause local inflammations, or induce degenerative or malignant processes. The very limited development of the pathogen as well as the possible direct role of the chlamydial elementary bodies and toxins in the pathogenesis are discussed.

Animals↗
PubMed1979

Mucus-stimulating substances in human body fluids assayed in an invertebrate mucous cell system.

An in vitro cell system has been shown to respond differentially to body fluids from normal subjects and from those with disorders of mucus secretion. The urn cell complex of the marine invertebrate Sipunculus nudus responds to mucus-stimulating substances (MSS) in normal human lacrimal fluids and stool filtrates by producing mucus. The process of mucus secretion can be directly observed, and the amount produced can be measured, in a calibrated light microscope. MSS are decreased in lacrimal fluids of patients with dry-eye conditions, while they are periodically increased in filtered stools of patients with acute Shigella dysentery and acute cholera. MSS are remarkably increased isotonic dilutions of sera of rabbits with acute mucoid enteritis, but are absent from sera of normal rabbits. MSS are present in isotonic dilutions of normal human sera which are heated to 85 degrees C for 4 minutes, but are absent from similarly processed sera of immunosuppressed patients. Mean MSS values of heated sera of children with cystic fibrosis are higher than those of controls. The active factor in tears and serum is a large molecule and is heat-stable.

Animals↗
PubMed1978

A new group of mitogenic lectins from invertebrate sources.

In the haemolymph of the Tridacnid bivalve clams anti-galactans occur which do not have only glycosubstance precipitating and cell agglutinating properties, but also show mitogenic activity with respect to the blast transformation of human peripheral lymphocytes. This new property can be inhibited in a specific way by galactans and is destroyed by the degradation of the mitogenic lectin into subunits by polymer bound pronase. Quite a number of invertebrate haemolymph samples and snail albumin gland extracts, containing agglutinin activity, proved to have no mitogenic potency. The only exception was found in an extract of the snail albumin gland of Ampullaria canaliculata which contained a strong mitogen of the lectin type.

Agglutinins↗
PubMed1980

Bluetongue and epizootic hemorrhagic disease virus isolation from vertebrate and invertebrate hosts at a common geographic site.

One serotype of bluetongue virus (BTV) and two serotypes of epizootic hemorrhagic disease virus (EHDV) were isolated from vertebrate and invertebrate hosts on a farm in Colorado. The isolations were from blood samples collected a week apart from a dairy heifer with stomatitis and laminitis; EHDV serotypes 1 and 2 were isolated from the first blood sample, and BTV serotype 13 and EHDV serotype 1 were isolated from the second. Antibodies to EHDV and BTV were detected in the serum from this heifer. Both EHDV serotypes and BTV serotype 13 were isolated from pools of female biting gnats (Culicoides variipennis) that had not had a recent blood meal. The BTV insect isolate was biologically transmitted by female gnats from an infected donor sheep to a recipient host sheep. Culicoides variipennis was the predominant insect collected during three nights of light trap captures at the farm.

Animals↗
PubMed1978

Possible mechanisms underlying bursting pacemaker discharges in invertebrate neurons.

Certain invertebrate neurons generate endogenous bursts of action potentials due to an underlying slow membrane potential oscillation. An early hypothesis for the oscillations proposed a high resting sodium conductance that led to the depolarizing phase, followed by activation of an electrogenic sodium pump coupled to chloride ions, leading to the hyperpolarizing phase. Recent findings contradict this hypothesis. Current thought implicates two conductances in the generation of the oscillations. The depolarizing phase is due to an increase in a sodium or a calcium conductance; the hyperpolarizing phase is due to a subsequent increase in a potassium conductance, which may be either voltage dependent or triggered by an influx of calcium ions. The observation of a negative slope conductance region in the membrane I-V characteristic supports this hypothesis. Bursting cells also usually exhibit anomalous rectification, i.e., a decrease in slope conductance with depolarization, in the I-V characteristic. This decrease may result from a decrease in an outward current or an increase in an inward current. The more important bursting membrane characteristics have been incorporated into an electronic analog. The analog confirms the appropriateness of the two-conductance hypothesis. It also suggests that potassium ion accumulation outside the cell membrane may enhance bursting activity.

Action Potentials↗
PubMed1983

Cytophilic receptors for foreignness and some factors which influence phagocytosis by invertebrate leucocytes: in vitro phagocytosis by amoebocytes of the snail Lymnaea stagnalis.

By means of in vitro phagocytosis it was demonstrated that macrophage-like blood cells of an invertebrate (amoebocytes of the pond snail Lymnaea stagnalis) possess cytophilic receptors for foreignness. These receptors are lectin molecules which are reversibly bound to the surface of the cells. Phagocytosis is dependent, beyond recognition of foreignness, on temperature and pH, and on the feeding condition of the snails.

Agglutinins↗
PubMed1983

The degradation of urate in liver peroxisomes. Association of allantoinase with allantoicase in amphibian liver but not in fish and invertebrate liver.

Allantoinase and allantoicase were co-purified from frog (Rana catesbeiana) liver. The ratio of the two enzyme activities remained constant during purification and was unchanged by a variety of treatments of the purified enzyme. These results suggest that allantoinase and allantoicase are located in the same protein. It was found that the two hepatic enzyme activities are also associated with the same protein in other frogs (Xenopus laevis and Rana nigromacultata), tadpoles (R. catesbeiana), and newts (Triturus pyrrhogaster). In contrast, allantoinase and allantoicase were found to be different proteins in marine fish and invertebrate liver.

Amidohydrolases↗
PubMed1983

[Food poisoning with marine animal toxins of invertebrate origin].

The consumption of seafood is increasing and hence the risk of poisoning. For this reason, the study of food poisoning caused by zootoxins from marine invertebrates has become of signal importance. These toxins come from bivalve molluscs and other species. Depending on the type of toxin concerned, poisoning attributable to molluscs may give rise to paralysis, caused by saxitossin, neurotoxic effects (gimbretoxin), or haemolysis (venerupin). Poisoning caused by coelenterates, echinoderms, cephalopods, Neptunea, abalone, crabs and lobsters is less common, and its clinical pictures and pathogenesis have not been fully established. In some instances, toxins presented in the phytoplankton ingested by these animals appear to be responsible, whereas in others its would seem that they themselves elaborate the active principles directly.

Animals↗
PubMedDate not supplied

[Isoelectric focusing of invertebrate actins].

A method combining advantages of both, charge electrophoresis and isoelectric focusing (IEF) was developed for analysing actins of different tissues. This method was used in investigations of actins from invertebrate muscle sources. Each type of actin has one isoform, pI of which is close to that of the smooth muscle beta-isoactin. Actins from different tissues of the mollusc Spisula s. were identical according to the IEF data.

Actins↗
PubMedDate not supplied

[Genome of the pogonophore Siboglinum fiordicum: organizational characteristics and divergence with respect to the genomes of representatives of certain types of invertebrates].

DNA of Pogonophora Siboglinum fiordicum was studied. DNA was isolated from ethanol fixed animals. It contains 40.5% GC according to the melting temperature and 39.3% GC as estimated by cation-exchange chromatography. From the reassociation kinetic data with a [125I] tracer 400 nucleotide long it is clear that 70% of the genome consists of repetitive sequences. The fast component (C0t less than 0.04) constitutes 11% of the genome, the intermediate (C0t 1/2 = 1.5, repetition frequency 1600)--59%. The unique sequences comprise about 30% of the genome. Experiments where [125I]tracers of increasing length were reassociated with driver DNA fragments 300 nucleotides long point out that at least 80% of the genome contains repetitive sequences, part of them being organized in short-period interspersion patterns. The hybridization of Pogonophora [125I]DNA fragments with DNA of invertebrates of other types--Echinodermata, Ascidia, Mollusca, Annelida--did not show any measurable homology between their DNAs neither in repetitive, nor in the unique fraction.

Animals↗
PubMed1995

Drosophila gp210, an invertebrate nuclear pore complex glycoprotein.

Monoclonal antibodies were used to localize the putative Drosophila homolog of mammalian nuclear pore complex glycoprotein, gp210, to Drosophila nuclear pore complexes. Both immunofluorescence and immunoelectron microscopy were performed. To the best of our knowledge, this establishes Drosophila gp210 as the first invertebrate gp210 homolog. Results of developmental studies demonstrated that like nuclear lamin and DNA topoisomerase II, gp210 is found abundantly in nonnuclear form early in embryogenesis where it presumably fuels the rapid assembly of new nuclei. Unlike thse other two proteins, gp210 levels are maximal early after wich they decrease significantly; in addition, nonnuclear gp210 found in early Drosophila embryos is apparently associated with membrane vesicles. These results have implications for understanding the regulation of higher eukaryotic nuclear pore complex behavior through development as well as for determining gp210 function genetically.

Animals↗