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At least 865 records · Page 48Linked to original sources
PubMed1994

Immunocytochemical distribution of neuropeptide F (NPF) in the gastropod mollusc, Helix aspersa, and in several other invertebrates.

The distribution of neuropeptide F (NPF) immunoreactivity in the snail, Helix aspersa, has been demonstrated by immunocytochemistry using 2 region-specific antisera. One, designated NPF3, was raised against a synthetic N-terminal fragment of Helix aspersa NPF; the other, designated PP221, was raised against the C-terminal hexapeptide amide of mammalian pancreatic polypeptide (PP) but cross-reacts fully with the analogous C-terminal region of Helix aspersa NPF. The distribution of NPF immunoreactivity has also been compared with that of FMRFamide using alternate serial sections of Helix aspersa ganglia. Results showed that NPF immunoreactivity was abundant and widespread in the central and peripheral nervous systems and the pattern of immunostaining obtained using both region-specific antisera was similar. Likewise, immunocytochemistry of neural tissues of a congeneric species, Helix pomatia, and 2 prosobranch gastropods, Buccinum undatum and Littorina littorea, produced similar staining patterns with both antisera. However, in the cephalopod mollusc, Loligo vulgaris, and the cestode, Moniezia expansa, positive immunostaining was only obtained with the C-terminal PP antiserum. Immunostaining of alternate serial sections of Helix aspersa ganglia with NPF3, and an antiserum raised to FMRFamide, showed that while a few neurones were immunoreactive with one antiserum only, in the majority, both immunoreactivities were co-localised. NPF thus appears to be an important neuropeptide of widespread distribution in Helix aspersa and the differential immunocytochemical staining obtained using the 2 region-specific antisera would suggest a high degree of primary structural conservation within the gastropod molluscs, but lack of conservation of the N-terminal region of the peptide in other invertebrate groups.

Amino Acid Sequence↗
PubMed1989

Occurrence of the (GATA)n sequences in vertebrate and invertebrate genomes.

Clusters of the tetranucleotide GATA are found throughout the mouse genome with a major concentration on the Y chromosome. In Drosophila melanogaster, by contrast, they have a significant concentration on the X chromosome. Largely on the basis of these sex chromosomal concentrations and on their transcriptional activity in the mouse, these simple sequence tracts have been thought to be important in sex-determining and X inactivation mechanisms in both vertebrates and invertebrates. In every tested case the interpretations of the data have been difficult and sometimes the data themselves have been conflicting. We demonstrate in this paper that significant tracts of (GATA)n are totally absent from ovine and bovine genomes and point out that none of the major clusters of these repetitive sequences are near any of the sex-determining genes in D. melanogaster. We conclude therefore that (GATA)n sequences are not conserved over long evolutionary time periods as has previously been thought. Their absence from at least two mammalian genomes places severe constraints on their possible functions.

Animals↗
PubMed1989

Biochemical correlates of genetic variation in marine lower invertebrates.

In this paper extensive data on enzyme variation in 23 species of coelenterates and sponges were used to investigate the possible correlation of levels of genetic variation with various parameters of enzyme molecular structure and function. The data provide an opportunity not only to look for such correlations for the first time in lower invertebrates, but also to study organisms with far higher average levels of genetic variability than those used in any previous work. A clear inverse relationship was found between enzyme subunit number and levels of polymorphism, with monomers being more variable than dimers or tetramers. No significant difference in polymorphism could be found in enzymes of the functional groups I and II of Gillespie and Langley (1974). Regulatory enzymes appeared to be significant relationship was observed between regulatory power and subunit structure which could bias this result. The results suggest that both neutralist and selectionist ideas may have a useful role to play in the understanding of the factors which can influence or limit levels of genetic variation.

Animals↗
PubMed1993

Neuropeptide Y inhibits human and invertebrate immunocyte chemotaxis, chemokinesis, and spontaneous activation.

1. In a concentration-dependent manner neuropeptide Y was found to be a potent inhibitor of the spontaneous activation of human granulocytes and macrophages as well as Mytilus edulis immunocytes. 2. Neuropeptide Y also inhibited the chemotaxic response of these immunocytes to the chemoattractant f-MLP. 3. Incubation of both the human and the invertebrate immunocytes in f-MLP (10(-9) M) causes "activation" as noted by random locomotion (chemokinesis). Neuropeptide Y also blocked f-MLP-induced chemokinesis. 4. The results suggest that neuropeptide Y may, in addition to other functions, serve as an endogenous regulator of immunocyte function.

Animals↗
PubMed1992

Corticotropin-releasing factor-induced immunosuppression in human and invertebrate immunocytes.

1. Corticotropin-releasing factor (CRF) appears to be a potentially important signal molecule in both vertebrate and invertebrate neuroimmune and autoimmunoregulatory processes. It appears to mimic the effects of alpha-melanocyte stimulating hormone (MSH) but has a longer duration of action. 2. alpha-Helical CRF, a specific inhibitor of CRF, antagonizes CRF-induced cellular immunosuppression but is ineffective in altering MSH-induced immunosuppression. 3. Both human and Mytilus immunocytes appear to have specific CRF receptors. 4. In another experiment, both CRF and MSH antagonize tumor necrosis factor stimulation of immunocytes. Again, alpha-helical CRF antagonizes only CRF activity, further suggesting the presence of a separate CRF receptor on these cells.

Animals↗
PubMed1981

Acute impact of an organophosphorus insecticide on microbes and small invertebrates of a mangrove estuary.

The effects of 24 to 72-hr exposure to fenthion (10(1)-10(3) ppb) were determined for a fungal community, nitrogen-fixing microbes, and representative meiofaunal and zooplankton invertebrates of a mangrove ecosystem. Also tested were the abilities of a benthic diatom and of fungi to grow in the presence of fenthion. Acute lethal, growth-inhibiting, or process-disrupting effects were not detected for exposures to less than 500 ppb fenthion. Results are compared with the findings of several other investigations of the impact of fenthion and other organophosphorus insecticides on non-target organisms.

Animals↗
PubMed1995

Fatty acid profiles of invertebrate iridescent viruses.

Eight invertebrate iridescent viruses (IVs) from diverse host taxa were grown in a common lepidopteran host, Galleria mellonella. The lipid composition of purified virus was assessed by fatty acid methyl esterase (FAME) analysis using a gas-liquid chromatograph. IV fatty acid profiles were markedly different from those of the host tissues. The interrelationships among the IVs did not follow previous serological and genetic findings. We conclude that FAME analysis is not a useful technique for revealing phylogenetic relationships among these viruses.

Fatty Acids↗
PubMed1978

Acute toxicity of phosphate ester mixtures to invertebrates and fish.

The acute toxicity of three commercial phosphate ester mixtures (hydraulic fluids) was tested against two invertebrates and four fishes. Pydraul 50E was more toxic than Houghtosafe 1120 in static and flow-through tests; Pydraul 115E was the least toxic. In flow-through tests these phosphate esters were less acutely toxic than PCB's. However, sublethal reactions to the phosphates suggest a need for chronic toxicity studies.

Animals↗
PubMed1990

Projectin is an invertebrate connectin (titin): isolation from crayfish claw muscle and localization in crayfish claw muscle and insect flight muscle.

A filamentous protein was isolated from crayfish claw muscle. This protein had physiochemical properties very similar to vertebrate skeletal muscle connectin (titin), although its apparent molecular mass (approximately 1200 kDa) was considerably lower than that of connectin (approximately 3000 kDa). Polyclonal as well as monoclonal antibodies against chicken skeletal muscle connectin reacted with the 1200 kDa protein from crayfish claw muscle. Conversely, polyclonal antibodies against crayfish 1200 kDa protein cross-reacted with chicken connectin. Circular dichroic spectra indicated the abundance of beta-sheet structure (approximately 60%). Low-angle shadowed images showed filamentous structures (0.2-0.5 microns) by electron microscopy. Proteolysis of the 1200 kDa protein by alpha-chymotrypsin or V8 protease rapidly resulted in formation of 1000 kDa or 1100 and 800 kDa peptides. The amino acid composition was very similar to those of vertebrate connectins and of honeybee flight muscle projectin. Based on the molecular weight and amino acid composition, the 1200 kDa protein is regarded to be crayfish projectin. Immunofluorescence and immunoelectron microscopy revealed that crayfish projectin was localized in the A/I junction area and A-band except for its centre region in crayfish claw muscles. Polyclonal antibodies against crayfish claw muscle projectin reacted with 1200 kDa projectin of honeybee and beetle flight muscle. A monoclonal antibody against chicken skeletal muscle connectin also reacted with honeybee and beetle projectin. Immunoelectron microscopic observations revealed that anti-crayfish projectin antibodies bound the connecting filaments linking the Z-line and the thick filaments up to the M-line of honeybee muscle sarcomere. Anti-crayfish projectin antibodies bound the I-band region near the Z-line of beetle flight muscle. It is concluded that the 1200 kDa projectin from crayfish claw muscle is an invertebrate connectin (titin). Recent work with locust flight muscle mini-titin (Nave & Weber, 1990) is in good agreement with the present study, except that the isolated mini-titin estimated as 600 kDa appears to be a proteolytic product (approximately 1100 kDa) of the parent molecule (approximately 1200 kDa).

Actin Cytoskeleton↗
PubMed1985

Isolation of polysomes from permissive and non-permissive invertebrate cell lines infected with chilo iridescent virus.

Chilo Iridescent virus (Iridovirus type 6 or CIV) infection results in a disaggregation of the heavy polyribosomes both in permissive and non-permissive invertebrate cell lines. The integrity of the viral genome is not involved in this event, as shown by the polysome absorbance profile on sucrose gradient, prepared from cells infected with UV treated virus. Heavy polysomes reappeared in permissive infected cells during the viral replication cycle.

Aedes↗
PubMedDate not supplied

Orienting reaction in invertebrates.

Changes in motor and vegetative indices in freshwater crayfish during sudden changes in the environmental situation are described. The results suggest that freshwater crayfish characterized by a sedentary lifestyle nevertheless constantly control the milieu in which they find themselves, by recording diverse changes in its parameters. Apparently the physiological nature of the reactions to "neutral" stimuli issuing from the milieu, is, in representatives of the higher invertebrates, very similar to that of the higher mammals, and may be described using the concepts of the orienting reflex and activity of an investigatory character which follows it. The question is posed in this context of the possibility of the appearance in this situation of emotional reactions of the animals investigated.

Animals↗
PubMed1996

Immunocytochemical electron microscopic study and western blot analysis of paramyosin in different invertebrate muscle cell types of the fruit fly Drosophila melanogaster, the earthworm Eisenia foetida, and the snail Helix aspersa.

The presence and distribution pattern of paramyosin have been examined in different invertebrate muscle cell types by means of Western blot analysis and electron microscopy immunogold labelling. The muscles studied were: transversely striated muscle with continuous Z lines (flight muscle from Drosophila melanogaster), transversely striated muscle with discontinuous Z lines (heart muscle from the snail Helix aspersa), obliquely striated body wall muscle from the earthworm Eisenia foetida, and smooth muscles (retractor muscle from the snail and pseudoheart outer muscular layer from the earthworm). Paramyosin-like immunoreactivity was localized in thick filaments of all muscles studied. Immunogold particle density was similar along the whole thick filament length in insect flight muscle but it predominated in filament tips of fusiform thick filaments in both snail heart and earthworm body wall musculature when these filaments were observed in longitudinal sections. In obliquely sectioned thick filaments, immunolabelling was more abundant at the sites where filaments disappeared from the section. These results agree with the notion that paramyosin extended along the whole filament length, but that it can only be immunolabelled when it is not covered by myosin. In all muscles examined, immunolabelling density was lower in cross-sectioned myofilaments than in longitudinally sectioned myofilaments. This suggests that paramyosin does not form a continuous filament. The results of a semiquantitative analysis of paramyosin-like immunoreactivity indicated that it was more abundant in striated than in smooth muscles, and that, within striated muscles, transversely striated muscles contain more paramyosin than obliquely striated muscles.

Animals↗
PubMed1977

Potential for employing the distribution of anomalous non-methylene-interrupted dienoic fatty acids in several marine invertebrates as part of food web studies.

A group of homologous, nonmethylene-interrupted dienoic fatty acids (NMID) recently reported in oysters has been found in several other shellfish species and also in other marine phyla. The distribution of most other "normal" fatty acids among several species of shellfish is basically similar but mantle lipids from two other molluscan species, both squid, differ radically. The squid mantle fatty acids do not include NMID, suggesting that in molluscs NMID may accumula-e primarily in filter-feeders or herbovores. The distribution of these anomalous fatty acid components in higher species suggests that they reflect invertebrates in the diet and are biochemically inert.

Animals↗
PubMed1975

Mineralization of invertebrate cartilage.

Although invertebrate cartilage tissues do not mineralize in nature, it is now reported for the first time that when excised gill cartilage tissue from Limulus (horse shoe crab) is placed in an appropriate incubation medium metastable to hydroxyapatite, mineralization will occur. The mineralization is temperature dependent, and takes place at 37 degrees but not at 20 degrees. Incubations in media metastable to calcite have not produced mineralization. Histologic examination of mineralized tissues showed mineral deposits predominantly within cells, and to a lesser extent in the matrix. X-ray diffraction of the deposited mineral revealed a typical biological hydroxyapatite pattern.

Animals↗
PubMed2000

Immunomodulation by recombinant human interleukin-8 and its signal transduction pathways in invertebrate hemocytes.

We report the presence of interleukin (IL)-8-immunoreactive molecules in hemocytes from the mollusc Mytilus galloprovincialis. Functional studies demonstrate that recombinant human (rh)IL-8 provokes conformational changes, induces chemotaxis, and increases bacterial phagocytic activity in hemocytes. rhIL-8 induces cell shape changes via protein kinase A and C pathways. These morphological changes are followed by reorganization of the actin microfilaments. The findings suggest that, as previously reported for other cytokines, IL-8 is well conserved and deeply involved in immune functions from invertebrates to mammals.

Animals↗
PubMed1998

Variation of microsatellite size homoplasy across electromorphs, loci, and populations in three invertebrate species.

Size homoplasy was analyzed at microsatellite loci by sequencing electromorphs, that is, variants of the same size (base pairs). This study was conducted using five interrupted and/or compound loci in three invertebrate species, the honey bee Apis mellifera, the bumble bee Bombus terrestris, and the freshwater snail Bulinus truncatus. The 15 electromorphs sequenced turned out to hide 31 alleles (i.e., variants identical in sequence). Variation in the amount of size homoplasy was detected among electromorphs and loci. From one to seven alleles were detected per electromorph, and one locus did not show any size homoplasy in both bee species. The amount of size homoplasy was related to the sequencing effort, since the number of alleles was correlated with the number of copies of electromorphs sequenced, but also with the molecular structure of the core sequence at each locus. Size homoplasy within populations was detected only three times, meaning that size homoplasy was detected mostly among populations. We analyzed population structure, estimating Fst and a genetic distance, based on either electromorphs or alleles. Whereas little difference was found in A. mellifera, uncovering size homoplasy led to a more marked population structure in B. terrestris and B. truncatus. We also showed in A. mellifera that the detection of size homoplasy may alter phylogenetic reconstructions.

Alleles↗
PubMed2005

Determination of steryl sulphates in invertebrate tissue by liquid chromatography-tandem mass spectrometry.

A method for the identification and quantification of underivatised steryl sulphates in invertebrates by liquid chromatography (LC) coupled with tandem mass spectrometry (MS) involving a single cleanup step has been developed. Negative electrospray ionisation and positive and negative atmospheric-pressure chemical ionisation (APCI) spectra of steryl sulphate showed pseudomolecular ions ([M+H-H2SO4]+ or [M-H]-). Collision-induced dissociation (CID) was efficient only in positive APCI. LC-MS in negative APCI was least susceptible to interference and possible differences in response factors. The detection limits (signal-to-noise ratio of 3) based on cholest-5-enyl-3-sulphate in positive and negative APCI modes are 3.66 and 0.73 pmol microL(-1), respectively. Calibration plots and response factors for cholest-5-enyl-3-sulphate relative to the internal standard, cholecalciferyl-3-sulphate, in both positive and negative polarities, were linear in the concentration range from 1.22 to 16.4 pmol microL(-1) with good coefficients of determination (R2 > 0.98). It is suggested that the structure elucidation of steryl sulphates is best achieved in CID positive APCI mode, whereas their quantification should be carried out using negative APCI.

Cholesterol↗