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At least 505 records · Page 28Linked to original sources
PubMed1987

The impact of angler groundbait on benthic invertebrates and sediment respiration in a shallow eutrophic reservoir.

In an experiment to determine the impact of angler baits, cereal or maggots were added to areas of sediment in a eutrophic reservoir at realistic rates, over a 12-week period. The densities of benthic invertebrate taxa were estimated before treatment, immediately after treatment, and, finally, after a 4-month recovery period. All taxa except the tubificid Limnodrilus hoffmeisteri were reduced in density by cereal baiting, the most sensitive being naidid worms and cladocerans. Recovery of the benthic community was not apparent after 4 months, although cyclopoid copepods were significantly more abundant in treated areas. Baiting with maggots had a qualitatively similar effect. Laboratory experiments to determine the rate of oxygen consumption by sediments treated with cereal bait suggest that demand for oxygen can be increased 100-fold by a single application of bait. It is suggested that this demand for oxygen could result in local deoxygenation under warm, calm conditions, and that this is the probable mechanism of the impact of cereal bait on benthic invertebrates.

Journal Article↗
PubMed1990

Distribution of antimony in contaminated grassland: 2--Small mammals and invertebrates.

Concentrations of antimony in invertebrates and small mammals from grasslands in the vicinity of an antimony smelter were significantly elevated compared to a control site. Higher concentrations of antimony were recorded in liver, lung and kidney tissue of herbivorous and insectivorous mammals from the contaminated sites. However, there is little evidence of bioaccumulation of antimony in food chains represented by the soil-vegetation-invertebrate-insectivore pathway of the grasslands, and little indication of significant accumulation by herbivorous mammals despite marked contamination of their diet.

Journal Article↗
PubMed1987

The status of the study of invertebrate neurons in tissue culture--phylum Arthropoda.

1. Neurobiological studies employing tissue culture are discussed for all invertebrate organisms in phylum Arthropoda and above. Only arthropod species have been investigated in these studies. 2. The members of phylum Arthropoda utilized were Periplaneta, Locusta, Drosophila, and Schistocerca. 3. Some of the initial studies of nerve cells in tissue culture were performed with Periplaneta and Drosophila; these studies were primarily concerned with differentiation, growth and development. 4. Cultured neurons from cockroach and locust have been used in pharmacological investigations of neurotransmitter receptors. 5. Embryos of the grasshopper Schistocerca were cultured in series of developmental studies related to axon guidance and peripheral nerve formation. 6. Recent studies with Drosophila neurons in vitro have applied a genetic approach to the investigation of molecular properties and function of the axonal sodium channel. 7. An overall view of neuronal tissue culture of invertebrates and analysis of the various areas of research is presented.

Animals↗
PubMed1988

Immunohistochemical demonstration of S-100 protein in the brain neurosecretory cells of invertebrates (insects and earthworms).

This immunohistochemical study demonstrated the presence of S-100 protein (-like substance) in the nervous systems of some invertebrate animals. The immunoreactivity of S-100 protein was detected in some neurosecretory cells, but not in glial cells in the brains (cerebral ganglia) of silkworms, cockroaches and earthworms. The immunoreactive nerve fibers extended to the neurohemal organs. These results suggested the possibility that S-100 protein (-like substance) may act as a neurohormone or carrier protein in invertebrate animals.

Animals↗
PubMed1992

Fractionation of DNA from marine invertebrate (Maja crispata, Mytilus galloprovincialis) haemolymph by alkaline elution.

1. An alkaline elution procedure for the detection of DNA damage in marine invertebrate haemolymph has been developed. 2. Provided that three criteria are optimized, such as buffer composition, small filter pores (0.22 microns GVWP 025 00, Millipore), and optimal amounts of haemolymph applied, flow rates may be changed within the range of 0.2 ml/min to 0.05 ml/min without adverse back-pressure on the filter and without blocking filter pores. 3. Under optimal conditions, 70% of mussel haemolymph DNA, and 80% of crab haemolymph DNA will be retained on the filter after 6 hr of elution, indicating shorter DNA in mussel haemolymph. 4. The technique is applicable for testing the in vivo effects of different compounds on DNA in marine invertebrates, and to measurements of DNA damage in naturally exposed mussels. 5. This argues an important case for the use of alkaline elution technique for assessment of environmental genotoxicity, and especially for investigation of DNA damage in different marine organisms which cover a broad range in their DNA molecular weights.

Animals↗
PubMed1982

The use of specific ligands for the vertebrate acetylcholine receptor in the characterization of invertebrate acetylcholine receptors.

1. The interaction of two specific ligands for the vertebrate nicotinic acetylcholine receptor were investigated on the solubilized form of a proposed acetylcholine receptor from the invertebrate Limulus polyphemus. 2. The affinity agent 4-(N-maleimodo)benzyltrimethylammonium iodide exhibited no effect on the binding of alpha-bungarotoxin to the Limulus receptor protein. 3. Torpedo acetylcholine receptor antibody neither inhibited alpha-bungarotoxin binding nor produced any alteration in the sedimentation profile of the Limulus receptor. 4. The lack of interaction of 4-(N-maleimido)benzyltrimethylammonium iodide and Torpedo acetylcholine receptor antibody with the Limulus acetylcholine receptor was interpreted to reflect significant difference between the molecular structures of this invertebrate receptor and the acetylcholine receptor of vertebrate.

Acetylcholine↗
PubMed2004

A comparative study of the expression of CYP1A and CYP4 genes in aquatic invertebrate (freshwater mussel, Unio tumidus) and vertebrate (rainbow trout, Oncorhynchus mykiss).

CYP1A1 induction has been widely studied in vertebrates and is used as an indicator of exposure to persistent pollutants like dioxins, polychlorobiphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs), especially in fish. Little work on this enzyme has been carried out in invertebrates, and results have suggested enzymatic or gene differences with the vertebrate isozyme. To date, a CYP4 isozyme has been characterized and sequenced in the marine mussel, Mytilus galloprovincialis, but no CYP1A invertebrate sequence has been found. The aim of this study was to identify CYP1A and CYP4 transcripts in the freshwater bivalve, Unio tumidus, and to compare their expression with those of the rainbow trout, Oncorhynchus mykiss, after treatment with the specific CYP1A1 and CYP4 vertebrate inducers, Aroclor 1254 and diethylhexylphthalate (DEHP), respectively. In spite of numerous amplification conditions and primer combinations tested, which had been successful in fish, no CYP1A sequence was amplified on cDNA of the digestive gland from either control and Aroclor-treated mussels. On the other hand, CYP4 transcripts were amplified in digestive glands from control and DEHP-treated mussels. As opposed to fish, no induction of this isozyme was obtained in mussels after phthalate treatment.

Amino Acid Sequence↗
PubMed2005

Over-expression, purification and characterization of the oligomerization dynamics of an invertebrate mitochondrial creatine kinase.

Mitochondrial creatine kinase (MtCK) plays a central role in energy homeostasis within cells that display high and variable rates of ATP turnover. Vertebrate MtCKs exist primarily as octamers but readily dissociate into constituent dimers under a variety of circumstances. MtCK is an ancient protein that is also found in invertebrates including sponges, the most primitive of all multi-cellular animals. We have cloned, expressed, and purified one of these invertebrate MtCKs from a marine polychaete worm, Chaetopterus variopedatus (CVMtCK). Size exclusion chromatography and dynamic light scattering (DLS) were used to characterize oligomeric state in comparison with that of octameric chicken sarcomeric isoform (SarMtCK). At protein concentrations >1 mg/ml, CVMtCK was predominantly octameric (>90%). When diluted to 0.1 mg/ml, CVMtCK dissociated into dimers much more rapidly than SarMtCK when observed under identical conditions. The rate of dissociation for both MtCKs increased as temperature rose from 2 to 28 degrees C, and in CVMtCK, fell at higher incubation temperatures. The fraction of octameric CVMtCK at equilibrium increased with temperature and then fell. Temperature transition studies showed that octamers and dimers were rapidly interconvertible on a similar time scale. Importantly, when CVMtCK was converted to the transition state analog complex (TSAC), both size exclusion chromatography and DLS showed that there was minimal dissociation of octamers into dimers while SarMtCK octamers were highly unstable as the TSAC. These results clearly show distinct differences in octamer stability between CVMtCK and SarMtCK, which could impact function under physiological circumstances. Furthermore, the large yield of recombinant protein and high stability of CVMtCK in the TSAC suggest that this protein might be a good target for crystallization efforts.

Adenosine Diphosphate↗
PubMed2004

Ethological analyses of crayfish behavior: a new invertebrate system for measuring the rewarding properties of psychostimulants.

Recent investigations in invertebrate neurobiology have opened up a new line of research into the basic behavioral, neurochemical and genomic alterations that accompany psychostimulant drug exposure. However, the extent to which such findings relate to changes in motivational and learning processes, such as those that typify drug addictions, remains unclear. The present study addressed this issue in the crayfish, Orconectes rusticus. The first set of experiments demonstrated that intramuscular injections of cocaine and amphetamine have robust and distinguishable effects on crayfish behavior. In the second part of the study, the reinforcing properties of psychostimulants were tested in a series of conditioned place preference experiments. Amphetamine and, to a lesser extent, cocaine were both found to serve as rewards when their intra-circulatory infusion was coupled to a distinct visual environment. The monoaminergic regulation of behavior has been extensively studied in decapod crustaceans and the present experiments demonstrated that (mammalian) drugs of abuse, capable of interfering with monoamine chemistry, are similarly rewarding to crayfish. Behavioral studies in crayfish can provide a complementary approach to using other invertebrate species in addiction research.

Amphetamine↗
PubMed2005

Biotreatment of wastewater using aquatic invertebrates, Daphnia magna and Paramecium caudatum.

A number of major changes have occurred over the past few years, which give cause for a re-examination of conventional wastewater treatment methods. Among these are growing problems of worldwide energy and food shortages and nutrients not removed by conventional secondary processes causing algal blooms and other problems in the receiving waters. The global increase in wastewater calls for innovative low cost technology approaches to its recycling. Biotreatment systems, utilizing living organisms are receiving growing attention since they are ecologically sound, cheap and applicable in areas without land constraints. Filter feeders (both invertebrates and vertebrates) are promising in this area since they can remove suspended organic matter and bacteria, even in the size range of microns. In the present study biological treatment of municipal wastewater using two invertebrates--Paramecium caudatum, a protozoan and Daphnia magna, a cladoceran was investigated. Analysis at pre-experimental and post-experimental stages revealed the potential of these species in abatement of water pollution. D. magna was more efficient than P. caudatum in laboratory-scale studies.

Animals↗
PubMed2005

Accumulation of trinitrotoluene (TNT) in aquatic organisms: part 2--Bioconcentration in aquatic invertebrates and potential for trophic transfer to channel catfish (Ictalurus punctatus).

The potential of TNT to accumulate in aquatic organisms was assessed by determining bioconcentration factors for TNT and TNT biotransformation products using two benthic invertebrates (Chironomus tentans and Lumbriculus variegatus), and by determining the bioaccumulation factor of TNT and TNT biotransformation products due to TNT exposure via feeding for channel catfish (Ictalurus punctatus). In all three species, TNT was rapidly biotransformed resulting in minimal accumulation. The bioconcentration factors for parent TNT ranged from 3 to 4 ml g(-1) for the invertebrates studied, while the TNT bioaccumulation factor for catfish via oral exposure of food pellets was 2.4x10(-5) g g(-1) based on the concentration of TNT in the food pellet. As indicated by this small bioaccumulation factor, TNT accumulation in channel catfish through trophic transfer would be negligible compared to aqueous exposure (previously reported BCF of 0.79 ml g(-1)). TNT extractable biotransformation products accumulated to a greater degree than parent TNT for all three species. In addition, a large fraction of the radioactivity within all three species resisted solvent extraction. The highest bioconcentration factors occurred in L. variegatus with extractable radioactivity measuring 76 ml g(-1) and total radioactivity measuring 216 ml g(-1). Because the bioaccumulation of TNT is very low compared to the bioaccumulation of its biotransformation products, further research including identifying and determining the relative toxicities of these biotransformation products is necessary to fully evaluate the environmental risk posed by exposure to TNT.

Animals↗
PubMed2003

EST analysis of the cnidarian Acropora millepora reveals extensive gene loss and rapid sequence divergence in the model invertebrates.

A significant proportion of mammalian genes are not represented in the genomes of Drosophila, Caenorhabditis or Saccharomyces, and many of these are assumed to have been vertebrate innovations. To test this assumption, we conducted a preliminary EST project on the anthozoan cnidarian, Acropora millepora, a basal metazoan. More than 10% of the Acropora ESTs with strong metazoan matches to the databases had clear human homologs but were not represented in the Drosophila or Caenorhabditis genomes; this category includes a surprising diversity of transcription factors and metabolic proteins that were previously assumed to be restricted to vertebrates. Consistent with higher rates of divergence in the model invertebrates, three-way comparisons show that most Acropora ESTs match human sequences much more strongly than they do any Drosophila or Caenorhabditis sequence. Gene loss has thus been much more extensive in the model invertebrate lineages than previously assumed and, as a consequence, some genes formerly thought to be vertebrate inventions must have been present in the common metazoan ancestor. The complexity of the Acropora genome is paradoxical, given that this organism contains apparently few tissue types and the simplest extant nervous system consisting of a morphologically homogeneous nerve net.

Animals↗
PubMed2006

Interval timing by an invertebrate, the bumble bee Bombus impatiens.

Sensitivity to temporal information and the ability to adjust behavior to the temporal structure of the environment should be phylogenetically widespread. Some timing abilities, such as sensitivity to circadian cycles, appear in a wide range of invertebrate and vertebrate taxa [1,2]. Interval timing--sensitivity to the duration of time intervals--has, however, only been shown to occur in vertebrates [3,4]. Insect pollinators make a variety of decisions that would appear to require the ability to estimate elapsed durations. We exposed bumble bees to conditions in which proboscis extension was reinforced after a fixed duration had elapsed or after either of two fixed durations had elapsed. Two groups of bees were trained with a short duration (either 6 s or 12 s) and a long duration (36 s) in separate experimental phases (independent timing groups), whereas two other groups were trained with a short duration (either 6 s or 12 s) and long duration (36 s) always intermixed unpredictably (multiple timing groups). On long intervals, independent timing groups waited longer than mixed timing groups to generate the first response and responded maximally near the end of the interval. Multiple timing groups waited the same amount of time on average before generating the first response on both long and short intervals. On individual trials, multiple timing groups appeared to time either the long duration only or both the short and long durations: most trials were characterized by a single burst of responding that began between the short and long duration values or by two bursts of responding with the first burst bracketing the short value and the second burst beginning in anticipation of the long value. These results show that bumble bees learn to time interval durations and can flexibly time multiple durations simultaneously. The results indicate no phylogenetic divide between vertebrates and invertebrates in interval timing ability.

Animals↗
PubMed2004

Self-discrimination in colonial invertebrates: genetic control of allorecognition in the hydroid Hydractinia.

Sessile, colonial invertebrates display the ability to distinguish between their own tissues and those of unrelated members of the same species. These allorecognition responses play a fundamental role in maintaining the genetic and physiological integrity of the colony. While allorecognition responses have been observed in all major colonial invertebrate taxa, the genetics of the response has been addressed only in the ascidian Botryllus and, more recently, in the hydroid Hydractinia. In Botryllus, allorecognition is controlled by a single co-dominant locus. This review focuses on current developments on the genetics of allorecognition in Hydractinia.

Animals↗
PubMed2006

Toxicity assessment of metabolites of fungal biocontrol agents using two different (Artemia salina and Daphnia magna) invertebrate bioassays.

Fungal biocontrol agents (BCAs) have been marketed for control of crop pests, weeds, and diseases. However, BCAs may produce toxic metabolites, whose presence in the formulated products, in the crops and in the environment should be considered along with the associated risk. Two invertebrate models, viz. Artemia salina and Daphnia magna were used to assess the acute toxicity of seven BCA metabolites, characterized by different chemical nature and mode of action, namely alamethicin (ALA), paracelsin (PCS), antiamoebin (AAM), gliotoxin (GTX), destruxin A (DA), oosporein (OOS), and elsinochrome A (EA). The two invertebrates were very sensitive to all the metabolites examined, except OOS. The LC50s after 24 and 36 h exposures showed the following toxicity ranks: A. salina, DA > ALA > EA > GTX > AAM > PCS (LC50s ranging from 9.78 to 40.84 microg/ml at 24 h and from 2.92 to 18.56 microg/ml at 36 h); D. magna, DA > GTX = EA > ALA > PCS > AAM (LC50s ranging from 0.20 to 24.41 microg/ml at 24h and from 0.16 to 11.98 microg/ml at 36 h). LC50 of OOS to D. magna increased dramatically in 36 h exposure, compared to 24 h exposures (5.84 and 68.40 microg/ml, respectively). A. salina and D. magna proved to be suitable models for rapid and inexpensive screening of toxicity of BCAs at an early stage of product development.

Animals↗
PubMed2005

Transmission of freshwater myxozoans during the asexual propagation of invertebrate hosts.

The phylum Myxozoa contains over 1350 species almost all of which are considered to be obligate parasites of aquatic animals. The phylum is composed of two classes, the Myxosporea and the Malacosporea, species of which are important pathogens responsible for severe economic losses in cultured fisheries. The life cycles of freshwater Myxozoa are believed to involve horizontal, indirect transmission, involving an invertebrate (oligochaetes or bryozoans) and a vertebrate host (fish or amphibians). Here, we describe myxozoan propagation through the fragmentation of invertebrate hosts to form new infected individuals. The two hosts examined are an oligochaete Lumbriculus variegatus infected with an unidentified myxosporean (Triactinomyxon sp.) and the bryozoan Fredericella sultana infected with the malacosporean Tetracapsuloides bryosalmonae which causes proliferative kidney disease, a major constraint of the European rainbow trout industry. Such intra-clonal propagation is a novel form of vertical transmission that is likely to be widespread within the Myxozoa and could form an important method by which some of these parasites maintain and proliferate within the aquatic environment.

Animals↗
PubMed2005

Microsporidia and the Society for Invertebrate Pathology [corrected]: a personal point of view.

In this overview, I trace the history of the study of microsporidia, with special emphasis on the collegial relationships that developed at the international level and were fostered by the establishment of the Society for Insect Pathology, which later became the Society for Invertebrate Pathology. Study of these organisms of invertebrates in the early days seemed to be mere curiosities, but it soon became clear that they were major disease-causing agents in insects, and later even in vertebrates, especially humans with compromised immune systems. Though microsporidia have not proven effective as pesticides, they do play a role in the regulation of insect populations, especially insects such as the gypsy moth, grasshoppers, and occasionally mosquitoes.

Animals↗
PubMed2006

Molecular cloning of an invertebrate goose-type lysozyme gene from Chlamys farreri, and lytic activity of the recombinant protein.

Lysozyme is a widely distributed hydrolase possessing lytic activity against bacterial peptidoglycan, which enables it to protect the host against pathogenic infection. In the present study, the cDNA of an invertebrate goose-type lysozyme (designated CFLysG) was cloned from Zhikong scallop Chlamys farreri by expressed sequence tag (EST) and rapid amplification of cDNA ends (RACE) techniques. The full-length cDNA of CFLysG consisted of 829 nucleotides with a canonical polyadenylation signal sequence AATAAA and a poly(A) tail, and an open reading frame (ORF) of 603 bp encoding a polypeptide of 200 amino acid residues with a predicted molecular weight of 21.92 kDa and theoretical isoelectric point of 7.76. The high similarity of CFLysG with goose-type (g-type) lysozymes in vertebrate indicated that CFLysG should be an invertebrate counterpart of g-type lysozyme family, which suggested that the origin of g-type lysozyme preceded the emergence of urochordates and even preceded the emergence of deuterostomes. Similar to most g-type lysozymes, CFLysG possessed all conserved features critical for the fundamental structure and function of g-type lysozymes, such as three catalytic residues (Glu 82, Asp 97, Asp 108). By Northern blot analysis, mRNA transcript of CFLysG was found to be most abundantly expressed in the tissues of gills, hepatopancreas and gonad, weakly expressed in the tissues of haemocytes and mantle, while undetectable in the adductor muscle. These results suggested that CFLysG could possess combined features of both the immune and digestive adaptive lysozymes. To gain insight into the in vitro lytic activities of CFLysG, the mature peptide coding region was cloned into Pichia pastoris for heterogeneous expression. Recombinant CFLysG showed inhibitive effect on the growth of both Gram-positive and Gram-negative bacteria with more potent activities against Gram-positive bacteria, which indicated the involvement of CFLysG in the innate immunity of C. farreri.

Amino Acid Sequence↗