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At least 343 records · Page 19Linked to original sources

PubMed2000

Collagenolytic protease preparations from invertebrates: biochemical aspects of medical and cosmetological applications.

Collagenolytic proteases from invertebrates, the active matter of new structure-destroying enzyme preparations (Collagenase from hydrobionts, Polycollagenase-K, Fermenkol), ensure deep hydrolysis of polypeptide substrates (native or partially denatured collagen types, elastin, fibrin, hemoglobin, and casein) that cannot be attained by collagenases and serine proteases. Biochemical properties of collagenolytic proteases from invertebrates, techniques and doses that may be important for elaboration and employment of preparations based on this complex are described.

Animals↗

PubMed2000

Hedgehog signaling in vertebrate and invertebrate limb patterning.

Invertebrate and vertebrate limbs have very different anatomies and modes of development. Despite these differences, recent studies demonstrate that a significant overlap exists in the signals used to pattern invertebrate and vertebrate limbs. One of these signaling molecules is Hedgehog, a secreted protein that functions to coordinate growth and proliferation along the anterior-posterior axis of developing limbs. Recent studies indicate that the mechanism of action, regulation and function of Hedgehog signaling in Drosophila and vertebrate limb development are often quite similar, yet at other times are distinct. Here we highlight the similarities and differences between the use of Hedgehog signaling in these two systems.

Animals↗

PubMed2002

Differential display analysis of gene expression in invertebrates.

Screening for differentially expressed genes is a straightforward approach to study the molecular basis for changes in gene expression. Differential display analysis has been used by investigators in diverse fields of research since it was developed. Differential display has also been the approach of choice to investigate changes in gene expression in response to various biological challenges in invertebrates. We review the application of differential display analysis of gene expression in invertebrates, and provide a specific example using this technique for novel gene discovery in the nematode Caenorhabditis elegans.

Animals↗

PubMed1999

Germline development in vertebrates and invertebrates.

In all animals information is passed from parent to offspring via the germline, which segregates from the soma early in development and undergoes a complex developmental program to give rise to the adult gametes. Many aspects of germline development have been conserved throughout the animal kingdom. Here we review the unique properties of germ cells, the initial determination of germ cell fates, the maintenance of germ cell identity, the migration of germ cells to the somatic gonadal primordia and the proliferation of germ cells during development invertebrates and invertebrates. Similarities in germline development in such diverse organisms as Drosophila melanogaster, Caenorhabditis elegans, Xenopus laevis and Mus musculus will be highlighted.

Animals↗

PubMed1999

Homology and convergence in vertebrate and invertebrate nervous systems.

Each year the meeting of the American Neuroscience Society attracts over 20,000 members, reflecting the explosion of interest in this field that has occurred over the past few decades. Researchers from many disciplines are focusing their skills on the investigation of every aspect of nervous systems, and neuroscience now encompasses the entire range of endeavour from the study of the single molecules that make up neural membranes to the non-invasive observation of neural function in animals behaving in their natural environments. Advances over the past three decades in our understanding of nervous systems are impressive and come from a multifaceted approach to the study of both vertebrate and invertebrate animals. An almost unexpected by-product of the parallel investigation of vertebrate and invertebrate nervous systems that is explored in this article is the emergent view of an intricate web of evolutionary homology and convergence exhibited in the structure and function of the nervous systems of these two large, paraphyletic groups of animals.

Animals↗

PubMed2006

A serum factor that recalcifies demineralized bone is conserved in bony fish and sharks but is not found in invertebrates.

We investigated the evolutionary origin of a serum activity that induces calcification within a type I collagen matrix, an activity previously described in rat and bovine serum. Serum was obtained from vertebrates with calcified tissues (bony fish and shark), vertebrates without calcified tissues (lamprey and hagfish), and three invertebrates (marine worm, crab, and sea urchin). Serum from the bony fish and shark proved to contain a potent nucleator of collagen calcification; like the previously described calcifying activity in rat serum, the fish and shark activities are both able to recalcify a demineralized rat tibia when tested in Dulbecco's modified Eagle medium containing as little as 1.5% of the respective serum and have an apparent molecular weight of 50-150 kDa. No calcifying activity could be detected in any of several experimental tests of invertebrate or hagfish serum. Weak calcifying activity could be detected in lamprey serum, but calcification was restricted to the growth plate of the decalcified tibia, with no detectable calcification in the type I collagen of the midshaft. These studies reveal a correlation between the evolutionary timing of the appearance of calcified tissues in vertebrates and the appearance of the serum activity that initiates calcification within collagen and, therefore, support the hypothesis that this serum activity may play a role in normal calcification of bone.

Animals↗

PubMed2005

Acute toxicity value extrapolation with fish and aquatic invertebrates.

Assessment of risk posed by an environmental contaminant to an aquatic community requires estimation of both its magnitude of occurrence (exposure) and its ability to cause harm (effects). Our ability to estimate effects is often hindered by limited toxicological information. As a result, resource managers and environmental regulators are often faced with the need to extrapolate across taxonomic groups in order to protect the more sensitive members of the aquatic community. The goals of this effort were to 1) compile and organize an extensive body of acute toxicity data, 2) characterize the distribution of toxicant sensitivity across taxa and species, and 3) evaluate the utility of toxicity extrapolation methods based upon sensitivity relations among species and chemicals. Although the analysis encompassed a wide range of toxicants and species, pesticides and freshwater fish and invertebrates were emphasized as a reflection of available data. Although it is obviously desirable to have high-quality acute toxicity values for as many species as possible, the results of this effort allow for better use of available information for predicting the sensitivity of untested species to environmental contaminants. A software program entitled "Ecological Risk Analysis" (ERA) was developed that predicts toxicity values for sensitive members of the aquatic community using species sensitivity distributions. Of several methods evaluated, the ERA program used with minimum data sets comprising acute toxicity values for rainbow trout, bluegill, daphnia, and mysids provided the most satisfactory predictions with the least amount of data. However, if predictions must be made using data for a single species, the most satisfactory results were obtained with extrapolation factors developed for rainbow trout (0.412), bluegill (0.331), or scud (0.041). Although many specific exceptions occur, our results also support the conventional wisdom that invertebrates are generally more sensitive to contaminants than fish are.

Animals↗

PubMed2000

The toxicity of a neem insecticide to populations of culicidae and other aquatic invertebrates as assessed in in situ microcosms.

Microcosm trials were conducted with the botanical insecticide Margosan-O(R) to assess the potential hazards of the product to aquatic organisms. Laboratory chronic bioassays with water from the treated microcosms were conducted to provide an estimate of the residual effect of Margosan-O. Results from chronic tests showed Margosan-O toxicity to be greater in the laboratory exposures than in situ with Culicidae larvae exposed to the same concentrations. Residue analyses of the active ingredient, azadirachtin, determined that it had a half-life of 36 to 48 h in water exposed to natural sunlight. Two applications of Margosan-O at the recommended application rate for pests did not harm aquatic invertebrates that are categorized as planktonic and filter feeding (Culex sp. and Daphnia sp.). However, the benthic invertebrate (Chironomus riparius) was affected by multiple applications of neem. These results show that the use of Margosan-O and possibly other neem extracts in or near aquatic environments could lead to disturbances in benthic populations and may cause decreases in numbers of organisms that are important in food web and nutrient cycling processes.

Animals↗

PubMed1997

Comparative bioaccumulation of chlorinated hydrocarbons from sediment by two infaunal invertebrates.

Bioaccumulation of chlorinated hydrocarbons (CHs) from field-contaminated sediments by two infaunal invertebrates, Rhepoxynius abronius (a non-deposit feeding amphipod) and Armandia brevis (a nonselective, deposit-feeding polychaete), was examined and species responses were compared. Sediments were selected over a large geographical area of the Hudson-Raritan estuary to assess the potential for bioaccumulation from a typical urban estuary. Unlike polycyclic aromatic hydrocarbons (PAHs) from these sediments, concentrations of CHs in interstitial water (IW) indicated that partition coefficients (Koc) were generally as expected, especially when based on predicted, nonsorbed, interstitial water CH concentrations (IWfree). Correlations between amphipod and polychaete tissue residues revealed that these species were responding similarly to a gradient of CH concentrations in sediment. While tissue residues and BAFloc (lipid/organic carbon normalized bioaccumulation factor) values for the trichlorobiphenyls were similar for both species, accumulation in the polychaete was three to 10 times higher for the more hydrophobic PCBs, which was attributed to differences in the route of exposure. A negative correlation between the bioaccumulation factor (BAF) and total organic carbon (TOC) was found for both species, which was expected according to equilibrium partitioning theory. Because it was assumed that the amphipod was not feeding in these tests and the polychaete was ingesting sediment, comparison of their tissue residues and bioaccumulation factors was useful for highlighting the importance of sediment ingestion, especially for short-term, nonequilibrium exposures. These results may also help elucidate the limitations associated with assessing bioaccumulation and the resultant toxic response in standard 10-day toxicity tests with similar invertebrates.

Animals↗

PubMed2004

HBMMD: an enhanced database of the microorganisms associated with deeper water marine invertebrates.

The Harbor Branch Marine Microbial Database (HBMMD) provides preliminary taxonomic identifications and features of microorganisms maintained in the Harbor Branch Oceanographic Institution Marine Microbial Culture Collection. The microbes are primarily derived from marine invertebrates such as sponges (phylum Porifera) and soft corals (phylum Cnidaria) found in deep water environments [>120 feet (>35 m) seawater]. The microbes isolated from within marine invertebrates represent some unique taxa and phylogenetic signatures. The database provides a user-friendly method to systemically search or sort a desired input. The site allows a powerful search for multiple parameters of any entry. Images of the microbes are contained within the database and can be accessed from the website. The HBMMD homepage is located at http://www.hboi.edu/dbmr/dbmr_hbmmd.html.

Animals↗

PubMed2004

Responses of invertebrate natural enemies to complex-structured habitats: a meta-analytical synthesis.

The structural complexity of habitats has been espoused as an important factor influencing natural-enemy abundance and food-web dynamics in invertebrate-based communities, but a rigorous synthesis of published studies has not heretofore been conducted. We performed a meta-analytical synthesis of the density response of natural enemies (invertebrate predators and parasitoids) to experimental increases and decreases in the structural complexity of their habitats using data from 43 published studies, reporting 62 independent taxa. Studies varied in structural complexity at two spatial scales (habitat and within-plant architecture) and comprised a diverse array of natural-enemy taxa (natural-enemy assemblage at large, the entire spider assemblage, hunting spiders, web-building spiders, mites, hemipterans, coccinellid beetles, carabid beetles, ants, and parasitoids). For all taxa combined, increasing habitat structure resulted in a large and significant increase in natural enemy abundance. Similarly, decreasing habitat structure significantly diminished natural enemy abundance. Separate meta-analyses at two spatial scales (habitat and within-plant architecture) found that increasing habitat complexity resulted in significant increases in abundance. In particular, manipulating levels of detritus at the habitat spatial scale had the strongest effect on natural enemy abundance. In general, most guilds of natural enemies were significantly affected when the structural complexity of the habitat was altered. Seven of nine natural enemy guilds were more abundant under conditions of increased habitat complexity, with hunting spiders and web-building spiders showing the strongest response followed by hemipterans, mites, and parasitoids. Spiders in particular were negatively affected when habitat structure was simplified. The mechanisms underlying the accumulation of natural enemies in complex-structured habitats are poorly known. However, refuge from intraguild predation, more effective prey capture, and access to alternative resources (alternative prey, pollen, or nectar), are possible candidates. Our analysis was unable to confirm that predators aggregate in complex-structured habitats because prey (mostly herbivores) are more abundant there. The results of this meta-analysis support the view that basal resources mediate top-down impacts on herbivores, and provide encouragement that manipulations of habitat complexity can be made in agroecosystems that will enhance the effectiveness of the natural enemy complex for more effective pest suppression.

Agriculture↗

PubMed2005

Data mining for protein-protein interactions in invertebrate model organisms.

Well-annotated genome databases are available for many invertebrate species, notably the fruitfly, Drosophila melanogaster, and the nematode, Caenorhabditis elegans. An adequate interpretation of this information at the biological level requires the exploration of the interactions between the gene products. Knowledge of protein interactions and the components of cell signalling pathways in the fly and worm are particularly valuable as hypotheses can be rapidly tested using the powerful genetic toolkits available. Invertebrates offer additional experimental advantages when attempting to characterise protein-protein interactions (PPIs). Their relatively small genome size compared to mammals helps to reduce missed interactions due to redundancy, and their function can be addressed using forward (mutants) and reverse (RNA interference) genetics. However, the researcher looking for evidence of PPIs for a protein of interest is faced with the challenge of extracting interaction data from sources that are highly varied, such as the results of microarray experiments in the unstructured text of research papers. This challenge is greatly reduced by a range of public databases of curated information, as well as publicly available, enhanced search engines, which can provide either direct experimental evidence for a PPI, or valuable clues for generating new hypotheses.

Animals↗

PubMed2004

Critical analysis of soil invertebrate biomarkers: a field case study in Avonmouth, UK.

During the period 1996-1999 a joint field research programme (BIOPRINT-II) funded by the European Union was undertaken. The main objective of this project was the deployment of biochemical fingerprint techniques of soil invertebrate biomarkers for assessing the exposure and effect of toxicants on soil invertebrates in the field. The aim was to apply these techniques in the field focusing on a a chronically polluted field near a lead and zinc smelter in Avonmouth (UK). Therefore six sites were selected from which organisms were either sampled or transplanted to or from the laboratory. The project has provided a unique opportunity to apply a series of biological test methodologies in order to determine the hazard posed to soil sustainability and by inference soil biodiversity and function. This work has attempted to understand the linkage between effects measured at the molecular or cellular level and relate these to changes at higher levels of biological organisation. Here we evaluated the links between biomarkers and soil function parameters. The paper aims to summarize and explore the necessary caveats that must be understood before soil biomarker test systems may be used to strengthen the risk assessment process.

Animals↗

PubMed2007

Developing Test Guidelines on invertebrate development and reproduction for the assessment of chemicals, including potential endocrine active substances- the OECD perspective.

The Organisation for Economic Co-operation and Development (OECD) Test Guidelines Programme is involved in the international harmonization and validation of test methods to evaluate effects of chemicals, including potential endocrine active substances. To meet their existing and foreseen regulatory needs in this area, OECD member countries have encouraged the development of test methods and their emergence at the OECD level. Validation activities are underway in countries and industry to ascertain the relevance and reliability of these tests to enable future regulatory acceptance. This includes work on development and (sexual) reproduction of aquatic invertebrates. What is the importance of mechanistic information in regulating chemicals, and how to address the issue of possible endocrine disruption in invertebrates while integrating these tests in a regulatory scheme are the current questions faced by the OECD countries.

Animals↗

PubMed2006

Spatial scale of autocorrelation of assemblages of benthic invertebrates in two upland rivers in South-Eastern Australia and its implications for biomonitoring and impact assessment in streams.

Spatial autocorrelation in ecological systems is a critical issue for monitoring (and a general understanding of ecological dynamics) yet there are very few data available, especially for riverine systems. Here, we report here on assemblage-level autocorrelation in the benthic-invertebrate assemblages of riffles in two adjacent, relatively pristine rivers in south-eastern Victoria, Australia (40-km reaches of the Wellington [surveys in summers of 1996 and 1997] and Wonnangatta Rivers [survey in summer of 1996 only], with 16 sites in each river). We found that analyses were similar if the data were resolved to family or to species level. Spatial autocorrelation was assessed by using Mantel-tests for the data partitioned into different sets of spatial separations of survey sites (e.g. 0-6 km, 6-12 km, etc.). We found strong small-scale (< or =6 km) autocorrelation in the Wellington River, which is consistent with known dispersal abilities of many aquatic invertebrates. Surprisingly, there were strong negative correlations at longer distance classes for the Wellington River in one of the two summers (20-40 km) and the Wonnangatta River (12-20 km). That two largely unimpacted, adjacent rivers should have such different autocorrelation patterns suggests that impact assessment cannot assume dependence or independence of sites a priori. We discuss the implications of these results for use of "reference" sites to assess impacts at nominally affected sites.

Animals↗

PubMed2006

Radionuclide concentrations in benthic invertebrates from Amchitka and Kiska Islands in the Aleutian Chain, Alaska.

Concentrations of 13 radionuclides (137Cs, 129I, 60Co, 152Eu, 90Sr, 99Tc, 241Am, 238Pu, 239,249Pu, 234U, 235U, 236U, 238U) were examined in seven species of invertebrates from Amchitka and Kiska Islands, in the Aleutian Chain of Alaska, using gamma spectroscopy, inductively coupled plasma mass spectroscopy, and alpha spectroscopy. Amchitka Island was the site of three underground nuclear test (1965-1971), and we tested the null hypotheses that there were no differences in radionuclide concentrations between Amchitka and the reference site (Kiska) and there were no differences among species. The only radionuclides where composite samples were above the Minimum Detectable Activity (MDA) were 137Cs, 241Am, 239,249Pu, 234U, 235U, 236U, and 238U. Green sea urchin (Strongylocentrotus polyacanthus), giant chiton (Cryptochiton stelleri), plate limpets (Tectura scutum) and giant Pacific octopus (Enteroctopus dofleini) were only tested for 137Cs; octopus was the only species with detectable levels of 137Cs (0.262 +/- 0.029 Bq/kg, wet weight). Only rock jingle (Pododesmus macroschisma), blue mussel (Mytilus trossulus) and horse mussel (Modiolus modiolus) were analyzed for the actinides. There were no interspecific differences in 241Am and 239,240Pu, and almost no samples above the MDA for 238Pu and 236U. Horse mussels had significantly higher concentrations of 234U (0.844 +/- 0.804 Bq/kg) and 238U (0.730 +/- 0.646) than the other species (both isotopes are naturally occurring). There were no differences in actinide concentrations between Amchitka and Kiska. In general, radionuclides in invertebrates from Amchitka were similar to those from uncontaminated sites in the Northern Hemisphere, and below those from the contaminated Irish Sea. There is a clear research need for authors to report the concentrations of radionuclides by species, rather than simply as 'shellfish', for comparative purposes in determining geographical patterns, understanding possible effects, and for estimating risk to humans from consuming different biota.

Alaska↗

PubMed1996

Morphine stimulates nitric oxide release from invertebrate microglia.

Morphine stimulates nitric oxide (NO) release in human endothelial cells. To determine whether this mechanism also occurs in invertebrates, the mussel Mytilus edulis was studied. Exposure of excised ganglia to morphine for 24 h resulted in a significant dose-dependent decrease in microglial egress that was naloxone sensitive. In coincubating the excised ganglia with morphine and the nitric oxide synthase inhibitor, N omega-nitro-L-arginine methyl ester (L-NAME), an increase in microglial egress was observed, suggesting that morphine may stimulate microglia to release NO. Morphine exposure to these cells in vitro resulted in NO release (39.4 +/- 4.9 nM), a phenomenon found to be naloxone sensitive (10(-6) M; NO level = 5.9 +/- 2.6 nM) and L-NAME sensitive (10(-4) M; NO level = 2.8 +/- 1.8 nM). Opioid peptides did not stimulate NO release, indicating that the process was mediated by the opiate alkaloid selective mu 3 receptor. Coincubation of microglia with L-arginine or the superoxide scavenger, superoxide dismutase, resulted in significantly higher NO levels observed following morphine stimulation. Taken together, the data demonstrate that morphine can stimulate NO release in cells obtained from an invertebrate that represents an animal 500 million years divergent in evolution from man, underscoring the significance of this process and further substantiating the critical importance of morphine as a naturally occurring signal molecule.

Animals↗

PubMed1988

The iodine-staining properties and fine structure of some mammalian and invertebrate glycogens.

Glycogens from mammalian and invertebrate sources have been compared by measuring the iodine-staining spectra of the debranched polymers and the debranched beta-amylase limit dextrins. From the results, it is concluded that, whereas the interior chains of each group of glycogen are very similar, the exterior chains of the mammalian glycogens generally contain a small number of longer chains which are not found in the invertebrate glycogens.

Ammonium Sulfate↗