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At least 487 records · Page 27Linked to original sources
PubMed1992

Insect muscle actins differ distinctly from invertebrate and vertebrate cytoplasmic actins.

Invertebrate actins resemble vertebrate cytoplasmic actins, and the distinction between muscle and cytoplasmic actins in invertebrates is not well established as for vertebrate actins. However, Bombyx and Drosophila have actin genes specifically expressed in muscles. To investigate if the distinction between muscle and cytoplasmic actins evidenced by gene expression analysis is related to the sequence of corresponding genes, we compare the sequences of actin genes of these two insect species and of other Metazoa. We find that insect muscle actins form a family of related proteins characterized by about 10 muscle-specific amino acids. Insect muscle actins have clearly diverged from cytoplasmic actins and form a monophyletic group emerging from a cluster of closely related proteins including insect and vertebrate cytoplasmic actins and actins of mollusc, cestode, and nematode. We propose that muscle-specific actin genes have appeared independently at least twice during the evolution of animals: insect muscle actin genes have emerged from an ancestral cytoplasmic actin gene within the arthropod phylum, whereas vertebrate muscle actin genes evolved within the chordate lineage as previously described.

Actins↗
PubMed1980

Occurrence of neurotensin-immunoreactive cells in the digestive tract of lower vertebrates and deuterostomian invertebrates. A correlated immunohistochemical and radioimmunochemical study.

In the mucosal epithelium of the digestive tract of two marine teleost bony fish, one cartilaginous fish, one cyclostome, and in that of two of three representatives of deuterostomian invertebrates studied, endocrine cells of open type were found, exhibiting immunoreactivity with antisera against C-terminal sequences of mammalian neurotensin and of the structurally closely related amphibian neurohormonal peptide xenopsin. From these observations, and from those of previous studies, it is suggested that neurotensin cells do not occur in the digestive tract mucosa until at the evolutionary level of the more highly developed deutoerostomian invertebrates. Three evolutionary stages seem to exist in the distribution pattern. The first stage, characterized by few, widely scattered cells, is found in the uro- and cephalochordates, the cyclostomes, the cartilaginous fish, and the stomachless bony fish. In the second stage, comprising the remaining submammalian classes, including more highly developed bony fish, the typical distribution pattern is that of numerous neurotensin immunoreactive cells in the antrum, pylorus, and duodenum. The final stage of neurotensin evolution is found in higher mammals and is characterized by a great density of neurotensin immunoreactive cells in the ileum.

Animals↗
PubMed1993

Drosophila melanogaster does not share the telomeric repeat sequence of another invertebrate, Ascaris lumbricoides.

The DNA at the chromosomal termini of all eukaryotes from which it has been isolated contains a characteristic sequence motif consisting of tandem arrays of a regular or irregular repeat unit. These terminal repeats are thought to be essential for the maintenance of the chromosome ends. The sequences of the terminal repeats of all vertebrates studied thus far are identical and are similar enough to those of higher plants and some protozoans to cross-hybridize. However, previous studies have not detected cross-hybridization between the DNA of Drosophila melanogaster and the terminal DNA sequences of any of several organisms tested. Recently, the first terminal DNA clone from a multicellular invertebrate, that of Ascaris lumbricoides, was reported also to consist of a tandem reiteration of a short sequence similar to those previously identified for other eukaryotes. Here I show that a probe for this sequence from A. lumbricoides fails to hybridize detectably to the DNA of D. melanogaster. Thus, in contrast to their conservation among vertebrates, the terminal chromosomal sequences appear not to be shared by all metazoan invertebrates.

Animals↗
PubMed1989

Immunohistochemical investigation of locust neuroparsin-like substances in several insects, in some other invertebrates, and vertebrates.

Anti-neuroparsin serum was immunohistochemically tested on brain and/or neurohemal organ from 40 insect species belonging to 13 orders, and from 8 non-insect invertebrate and 5 vertebrate representatives using the peroxidase-antiperoxidase procedure. In insects, immunostaining of only the A1 type of the protocerebral median neurosecretory cells was revealed in all species tested of Odonata, Dictyoptera, Isoptera and Orthoptera and in 2 species from the 9 other orders out of 13 orders tested. No immunostaining was detected in vertebrate and non-insect invertebrate species except in 2 annelid species out of 4 tested. The distribution of neuroparsin-like products in Coelomata appears to be restricted mainly to 4 phylogenetically close insect orders.

Amphibians↗
PubMed1991

Toxicity of microencapsulated permethrin to selected nontarget aquatic invertebrates.

Microencapsulated permethrin (penncapthrin) was evaluated under laboratory conditions for its toxicity toward several nontarget aquatic invertebrates. Average LC50 estimates for selected lotic invertebrates, based on a one hour dosing regime, were: 2.71 mg/L for Simulium vittatum, 4.59 mg/L for Hydropsyche spp., and 13.41 mg/L for Isonychia bicolor. In acute static tests with Daphnia magna, there was no significant difference (p less than or equal to 0.05) between the toxicity of penncapthrin at 96 h (LC50 range: 6.80-22.5 micrograms/L) and the EC formulation at 72 h (LC50 range: 0.6-21 micrograms/L). Comparatively, the toxicity of microencapsulated methyl parathion (penncap-m) was not significantly different from that of penncapthrin toward D. magna, the former having LC50 estimates ranging form 0.3-12.25 micrograms/L. LC50 estimates associated with Daphnia pulex ranged from 19 to 131 micrograms/L. The toxicity of penncapthrin and penncap-m toward D. pulex was difficult to determine because of frequent control mortality due to food deprivation resulting from the need to run tests for longer than 48 h. In successful tests, LC50 estimates ranged from 19 to 28 micrograms/L for penncapthrin and 0.08 to 25 micrograms/L for penncap-m after 72 h exposure. In long term toxicity tests, 95% of D. magna at 1 microgram/L, 44% at 10 micrograms/L, and 20% at 15 micrograms/L survived after 39 days exposure. Less than 15% of D. pulex survived over the same concentration range following 32 days exposure. Despite same drawbacks, long-term toxicity tests were more appropriate than short-term tests for evaluating microencapsulated pesticides because of reduced variability in LC50 estimates and lower control mortality.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1980

Inhibition of macromolecular synthesis in cells infected with an invertebrate virus (iridovirus type 6 or CIV).

Chilo Iridescent Virus (CIV), an invertebrate virus, rapidly inhibits cellular RNA, DNA and protein synthesis in permissive and non permissive vertebrate and invertebrate cell lines. The integrity of the viral genome is not required for inhibitory expression, since viral proteins solubilized from CIV by freezing and treatment with EDTA exhibit inhibitory properties similar to those of intact virions.

Aedes↗
PubMed1979

Cell fusion induced by invertebrate virus. Brief report.

Inoculation of invertebrate cells with Chilo Iridescent Virus (CIV) leads rapidly to massive formation of syncytia. This polykaryocytosis occurs at a high multiplicity of infection and does not require viral genome expression. Thus, cell fusion appears in non permissive conditions, and CIV suspensions rendered non infections by UV irradiation still retain the ability to produce rapid and extensive cell fusion. In the same way, some polykaryocytes could be detected in vertebrate cells (CV1 cell line). However, this process is more effective and faster in invertebrate cell systems.

Aedes↗
PubMed1996

Immunocytochemical evidence of PDGF- and TGF-beta-like molecules in invertebrate and vertebrate immunocytes: an evolutionary approach.

Immunoreactive platelet-derived growth factor-AB and transforming growth factor-beta 1 were demonstrated in invertebrate and vertebrate immunocytes by an immunocytochemical procedure. These factors are only present in phagocytic cells among invertebrate immunocytes, whereas in vertebrate immunocytes they are found in monocytes, granulocytes, lymphocytes, thrombocytes and platelets. These results, in agreement with previous reports, represent further evidence in favour of the hypothesis that Nature has followed a conservative strategy in using a common pool of signal molecules that have been highly conserved throughout evolution.

Animals↗
PubMed1998

Assessing Sediments from Upper Mississippi River Navigational Pools Using a Benthic Invertebrate Community Evaluation and the Sediment Quality Triad Approach

Benthic invertebrate samples were collected from 23 pools in the Upper Mississippi River (UMR) and from one station in the Saint Croix River (SCR) as part of a study to assess the effects of the extensive flooding of 1993 on sediment contamination in the UMR system. Sediment contaminants of concern included both organic and inorganic compounds. Oligochaetes and chironomids constituted over 80% of the total abundance in samples from 14 of 23 pools in the UMR and SCR samples. Fingernail clams comprised a large portion of the community in three of 23 UMR pools and exceeded abundances of 1,000/m2 in five of 23 pools. Total abundance ranged from 250/m2 in samples from pool 1 to 22,389/m2 in samples from pool 19. Abundance values are comparable with levels previously reported in the literature for the UMR. Overall frequency of chironomid mouthpart deformities was 3% (range 0-13%), which is comparable to reported incidence of deformities in uncontaminated sediments previously evaluated. Sediment contamination was generally low in the UMR pools and the SCR site. Correlations between benthic measures and sediment chemistry and other abiotic parameters exhibited few significant or strong correlations. The sediment quality triad (Triad) approach was used to evaluate data from laboratory toxicity tests, sediment chemistry, and benthic community analyses; it showed that 88% of the samples were not scored as impacted based on sediment toxicity, chemistry, and benthic measures. Benthic invertebrate distributions and community structure within the UMR in the samples evaluated in the present study were most likely controlled by factors independent of contaminant concentrations in the sediments.

Journal Article↗
PubMed2000

Stream Invertebrate Communities, Water Quality, and Land-Use Patterns in an Agricultural Drainage Basin of Northeastern Nebraska, USA.

We used invertebrate bioassessment, habitat analysis, geographic information system analysis of land use, and water chemistry monitoring to evaluate tributaries of a degraded northeast Nebraska, USA, reservoir. Bimonthly invertebrate collections and monthly water chemistry samples were collected for two years on six stream reaches to identify sources contributing to reservoir degradation and test suitability of standard rapid bioassessment methods in this region. A composite biotic index composed of seven commonly used metrics was effective for distinguishing between differentially impacted sites and responded to a variety of disturbances. Individual metrics varied greatly in precision and ability to discriminate between relatively impacted and unimpacted stream reaches. A modified Hilsenhoff index showed the highest precision (reference site CV = 0.08) but was least effective at discriminating among sites. Percent dominance and the EPT (number of Ephemeroptera, Plecoptera, and Trichoptera taxa) metrics were most effective at discriminating between sites and exhibited intermediate precision. A trend of higher biotic integrity during summer was evident, indicating seasonal corrections should differ from other regions. Poor correlations were evident between water chemistry variables and bioassessment results. However, land-use factors, particularly within 18-m riparian zones, were correlated with bioassessment scores. For example, there was a strong negative correlation between percentage of rangeland in 18-m riparian zones and percentage of dominance in streams (r(2) = 0.90, P < 0.01). Results demonstrate that standard rapid bioassessment methods, with some modifications, are effective for use in this agricultural region of the Great Plains and that riparian land use may be the best predictor of stream biotic integrity.

Journal Article↗
PubMed1999

Identification and localisation of nebulin as a thin filament component of invertebrate chordate muscles.

The giant actin-binding protein nebulin is regarded as a component of the thin filaments in vertebrate skeletal muscles, whereas the existence of nebulin in invertebrate muscles has not yet been demonstrated. Using the cross-reactivities of polyclonal antibodies raised against nebulin from muscles of trout and lamprey, we were able to identify nebulin in the myofibrils of the cephalochordate Branchiostoma lanceolatum (lancelet) by immunoblot and immunofluorescence techniques. The approximately 720-kDa protein is localised in the I-bands of the sarcomere, where vertebrate nebulin has previously also been shown to be localised. Since lancelets have a phylogenetically key position at the vertebrate/invertebrate boundary, the detection of a high-molecular-weight nebulin indicates that nebulin-like proteins may be common to striated muscles in all chordates and increases the probability that non-chordate invertebrates also possess nebulin-related proteins.

Animals↗
PubMed2004

Semiquantitative confocal laser scanning microscopy applied to marine invertebrate ecotoxicology.

Confocal laser scanning microscopy (CLSM) represents a powerful, but largely unexplored ecotoxicologic tool for rapidly assessing in vivo effects of toxicants on marine invertebrate embryo quality and development. We describe here a new semiquantitative CLSM approach for assessing relative yolk quantity in marine invertebrate embryos (harpacticoid copepods) produced by parents reared from hatching to adult in the polycylic aromatic hydrocarbon chrysene. This method is based on fluorogenic labeling of embryo yolk and subsequent statistical analysis of areal pixel intensities over multiple Z-series using a general linear model (GLM)-nested analysis of variance. The fluorescent yolk-labeling method described here was able to detect statistically significant differences in yolk concentrations in marine copepod (Amphiascus tenuiremis) eggs or embryos from females exposed to ultraviolet light and chrysene-contaminated sediments. Yolk intensities in embryos from females cultured throughout their life cycles in clean sediments were statistically identical with or without UV exposure. In contrast, yolk intensities in embryos of females cultured throughout their life cycle in chrysene-contaminated sediments were significantly higher in the non-UV-exposed treatment with chrysene at 2500 ng/g sediment (65.7% higher) and the UV-exposed treatment with chrysene at 500 ng/g sediment (76.6% higher).

Animals↗
PubMed2006

Molecular detection of marine invertebrate larvae.

The ecological patterns of many invertebrate larvae remain an ongoing mystery, in large part owing to the difficult task of detecting them in the water column. The development of nucleic-acid-based technology has the potential to resolve this issue by direct identification and monitoring of embryonic and larval forms in situ. We report herein on the successful development and application of nucleic-acid-based sandwich hybridization assays that detect barnacles using rRNA-targeted probes with both group-(order Thoracica) and species-(Balanus glandula) specificity. Primary results include the determination of target 18S rRNA sequences and the construction of "capture" probes for detection of larvae using hybridization techniques. In addition, we modified existing protocols for whole cell hybridization of invertebrate larvae as confirmation of the sandwich hybridization results. We used both hybridization techniques successfully in the laboratory on a plankton time series collected over 3 months, as well as a week-long in situ deployment of the technique in Monterey Bay, CA. The adaptability of this technology promises to be further applicable to various organisms and could be used to enhance our understanding of larval presence in the world's oceans.

Air Pressure↗
PubMed1988

Actin filaments are associated with the septate junctions of invertebrates.

Septate junctions are almost ubiquitous in the tissues of invertebrates but are never found in those of vertebrates. In spite of their widespread occurrence and hence obvious importance to the invertebrates, their precise function has remained elusive although they have been variously considered to be regions of cell-cell coupling, permeability barriers or adhesion sites. This report demonstrates that elements of the cytoskeletal system insert into the cytoplasmic face of septate junctions. Actin filaments, identified by virtue of their capacity to bind the S1 subfragment of rabbit myosin, are associated with the membranes of septate junctions. Cytochalasin D, an actin depolymerizer, leads to disorganization of the intramembrane components of these junctions. These data suggest that a primary role of septate junctions could be to maintain intercellular cohesion and hence tissue integrity. The assembly and localization of these junctions may be mediated, directly or indirectly, by the cytoplasmic actin filaments associated with their lateral membranes.

Actins↗
PubMed1984

A precipitin for human serum proteins as released under stress by a marine invertebrate, the marsh snail, Littorina irrorata.

A substance released into the environment by stressed marsh snails, Littorina irrorata, precipitates with the beta globulin and albumin fractions of human serum proteins. Other diverse invertebrate species may produce a similar substance. Invertebrate precipitins have not been widely reported, and none like the one described. Some physicochemical and adaptive characteristics of the snail precipitin are presented. This precipitin can be produced in large quantities and has potential application as a diagnostic reagent.

Animals↗
PubMedDate not supplied

Differential retrograde labelling with horseradish peroxidase (HRP) and Lucifer yellow (LY) in an invertebrate nervous system--HRP fluorescence and LY preservation limit choice of fixative.

The possible application of the combination of horseradish peroxidase (HRP) and Lucifer Yellow CH (LY) for differential retrograde labelling of a relatively large invertebrate nervous system requiring the enzymatic marker to be processed after fixation and sectioning was evaluated. In control experiments an HRP fluorescence induced by glutaraldehyde (GA) fixation was detected and its spectral properties were investigated. This fluorescence, however, does not occur after previous treatment of the tissue with depolymerized paraformaldehyde (PFA) instead of GA. PFA as a fixing agent is also necessary to yield maximum preservation of LY labelling during subsequent HRP histochemistry. Both findings strongly recommend the use of PFA instead of GA as fixative for the combination of HRP and LY. It is shown that the HRP/LY differential labelling technique renders a valid method for the study of the structural interactions at the fibre level of identified neurones in a relatively large invertebrate nervous system, also after retrograde tracing.

Animals↗
PubMed1994

Differential modulation of invertebrate hemocyte motility by CRF, ACTH, and its fragments.

Various reports have shown that invertebrate hemocytes are responsive to mammalian neuropeptides and cytokines. In the present study, we demonstrate that corticotropin-releasing factor (CRF) and adrenocorticotropin (ACTH) fragments (1-24), (1-4), (4-9), (1-13), (1-17), and (11-24) significantly stimulate molluscan hemocyte migration, and the whole sequence (1-39) and the fragment (4-11) have an inhibitory effect. Differences between species were found with respect to the response to individual fragments. Additionally, the (4-11) fragment was able to antagonize some of the stimulatory fragments (4-9) as well as tumor necrosis factor (TNF-alpha)-induced chemotaxis. Our results suggest that invertebrate hemocytes are able to respond to CRF and ACTH fragments that in turn provide further evidence of the complexity of intercellular signaling within the immune system in relatively primitive animals. Thus, auto- and neuroimmunoregulatory activities in mammals must have had an earlier beginning than previously believed.

Adrenocorticotropic Hormone↗