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At least 721 records · Page 40Linked to original sources
PubMed2001

Common developmental genetic mechanisms for patterning invertebrate and vertebrate brains.

Recent genetic studies on embryonic brain development in the fly Drosophila melanogaster together with investigations on early morphogenesis and patterning in the embryonic brain of the mouse revealed developmental mechanisms that are strikingly similar in insects and mammals. The homeotic (Hox) genes are expressed in a virtually colinear anteroposterior pattern in the developing posterior brain of insects and mammals, where they are required for the specification of segmental neuronal identity. The otd/Otx cephalic gap genes are expressed in the anterior brain of insects and mammals and are of central importance for its formation because in both phyla loss of otd/Otx2 causes the loss of the entire rostral brain. Specific Pax genes are involved in numerous aspects of brain development in both phyla. These developmental genetic findings reveal a striking evolutionary conservation of cephalic gap gene, homeotic gene, and Pax gene action in embryonic brain development that extends beyond gene structure to encompass patterned expression and function. This comparative evidence indicates that the genetic programs which direct embryonic brain development are remarkably conserved and lends further support to the hypothesis that a common molecular bauplan underlies brain development in invertebrates and vertebrates. In consequence, it seems increasingly likely that both modern brain types share their evolutionary origin in a common ancestral bilaterian brain which was established before the protostome-deuterostome divergence over 600 million years ago.

Animals↗
PubMed1999

A novel A-isoform-like inositol 1,4,5-trisphosphate 3-kinase from chicken erythrocytes exhibits alternative splicing and conservation of intron positions between vertebrates and invertebrates.

Based on the partial peptide sequence of inositol 1,4, 5-trisphosphate 3-kinase purified with 135 000-fold enrichment from chicken erythrocytes, cDNA-fragments were cloned by RT-PCR using degenerate oligonucleotides. Subsequent hybridization screening of an embryonic chicken cDNA library and 5'-RACE yielded a cDNA-contig of 2418 bp, encoding a 452 amino acid protein. The amino acid sequence shows the highest degree of homology with A-isoforms of inositol 1,4,5-trisphosphate 3-kinase (65% identities), whereas homology towards B and C isoforms was lower (57% and 52% amino acid identities respectively). These findings reveal a new tissue-specific pattern of A-isoform expression, a form which so far has only been found in brain and testes. Two overlapping lambda-genomic clones for chicken inositol 1,4,5-trisphosphate 3-kinase, isolated by hybridization screening, covered 18 499 bp of genomic sequence. This contig included four exons: three of them were present in all cDNA clones, whereas one was only represented in a single cDNA clone. In addition, the sequence of the latter differed from the other cDNAs by an in-frame deletion of 72 bp within the coding region for the catalytic domain of the enzyme. This divergent cDNA suggests the existence of alternative splice products, at least in embryonic tissue.A comparison of the position of introns, with the respective introns known from the corresponding gene from Caenorhabditis elegans, revealed a high degree of conservation of intron positions between vertebrates and invertebrates. Functional data for the enzyme suggests that the conserved exons represent defined functional protein modules.

Alternative Splicing↗
PubMed2000

[Thermal anomaly in waters of the Gulf of Marseilles during the summer of 1999. A partial explanation of the mortality of certain fixed invertebrates?].

During summer 1999, a massive mortality of attached benthic invertebrates was reported at several points along the French Mediterranean coast, east of the Rhône River. Such a wide geographical extension suggested the occurrence of a climatic anomaly as a direct or an indirect cause of this phenomenon. The systematic observations of surface water temperature (1 record/30 min) and vertical thermal structure from 0 to 55 m (semi-monthly frequency) performed by the service of observation of centre d'océanologie de Marseille since 1994 in the Gulf of Marseilles (northwestern Mediterranean) compared with historical data obtained for the summer periods (June till October) indicates a thermal anomaly during summer 1999. Although the surface temperatures do not strictly show exceptional values, the stability during long periods of high temperatures (24.1 degrees C +/- 0.5 in September, n = 1,018) and the thermal structure of the water column are remarkable. The vertical temperature profiles of 1999 reflect a general warming of 2-3 degrees C in the water layer overlying the thermocline, accompanied by its deepening (up to 30-40 m). This situation can be explained by the scarcity of NW winds with a marked drop of their relative frequency during July and October 1999 (13-27% versus 42%, mean value calculated from the previous 12 years) and the short duration of these windy periods (between 30 min and 5 h as a mean). Parallel to this, a large number of no wind registrations (125-250 h/month as a mean) were observed during this period. A similar thermal stratification, of lesser amplitude, associated with comparable meteorological conditions was also observed in 1997. The hypothesis that this summer 1999 temperature anomaly could constitute a partial explanation for the recorded massive mortality is discussed.

Animals↗
PubMed2000

[Massive mortality of marine invertebrates: an unprecedented event in northwestern Mediterranean].

An unprecedented mass mortality event has been observed at the end of the summer 1999 along the coasts of Provence (France) and Ligury (Italy). This event has severely affected a wide array of sessile filter-feeder invertebrates from hard-substratum communities, such as sponges (particularly the keratose sponges Hippospongia and Spongia), cnidarians (particularly the anthozoans Corallium, Paramuricea, Eunicella and Cladocora), bivalves, ascidians and bryozoans. Along the Provence coasts, the outbreak spread from east to west. Exceptionally high and constant temperatures of the whole water column (23-24 degrees C, for over one month, down to 40 m) could have determined an environmental context favourable to the mass mortality event. Like the thermal anomaly, the mortality is limited in depth. However, we cannot ascertain whether temperature had a direct effect on organisms or acted in synergy with a latent and/or waterborne agent (microbiological or chemical). Taking into account the global warming context in the NW-Mediterranean, monitoring programs of physical-chemical parameters and vulnerable populations should rapidly be set up.

Animals↗
PubMed1998

Role of the prophenoloxidase-activating system in invertebrate immunity.

The melanization reaction, which is a common response to parasite entry in invertebrate animals, especially arthropods, is due to the activity of an oxidoreductase, phenoloxidase. This enzyme is part of a complex system of proteinases, pattern recognition proteins and proteinase inhibitors constituting the so-called prophenoloxidase-activating system. It is proposed to be a non-self recognition system because conversion of prophenoloxidase to active enzyme can be brought about by minuscule amounts of molecules such as lipopolysaccharide, peptidoglycan and beta-1, 3-glucans from micro-organisms. Several components of this system recently have been isolated and their structure determined.

Animals↗
PubMed2001

Invertebrate myogenesis: looking back to the future of muscle development.

Recent studies in invertebrates have provided important mechanistic insights into several general aspects of muscle development. Two new genes have been identified that are involved in muscle fusion in Drosophila and a novel maternal component was shown to be responsible for myogenic determination in an ascidian. In addition, genetic analyses of nematode and Drosophila homologues of factors known to be myogenic regulators in other species yielded surprising findings about both the evolutionary conservation and divergence of these functions. Drosophila myogenesis has become a highly informative model for understanding the interplay between the signaling and transcriptional networks that underlie cell-fate specification during embryonic development.

Animals↗
PubMed2001

Cell migration in invertebrates: clues from border and distal tip cells.

Recent studies in two invertebrate systems, border cells in Drosophila melanogaster and distal tip cells in Caenorhabditis elegans, have provided important insight into the mechanisms of directed cell migration. These migrating cells are guided by extracellular signals, such as EGF, TGF-beta and netrin. In addition, metalloproteases alter the extracellular matrix of the tissue through which these cells migrate. Along the migratory path, migrating cells respond to changes in guidance signals by altering the expression of receptor signaling pathways. Finally, Dock180, CrkII and the GTPase Rac link the extracellular signals to the cellular machinery that controls cell motility.

Animals↗
PubMed2002

The GATA family (vertebrates and invertebrates).

Over the past year, vertebrate GATA factors have been found to participate directly in several signal-transduction pathways. Smad3, phosphorylated by TGF-beta signalling, interacts with GATA3 to induce differentiation of T helper cells. Hypertrophic stimuli act through RhoA GTPase and ROCK kinase to activate GATA4 in cardiac myocytes. In the liver, GATA4 is elevated by BMP and FGF signalling, and is able to bind to chromatin targets. Invertebrate GATA factors play a central role in specifying the mesendoderm.

Animals↗
PubMed1996

Programmed cell death in invertebrates.

Genetic studies of programmed cell death in Caenorhabditis elegans and Drosophila melanogaster have led to the identification of several invertebrate cell death genes. In C. elegans, ced-3 and ced-4 function to kill cells, whereas ced-9 protects cells from death. In Drosophila, the genes reaper and hid act in parallel to promote cell death. Characterization of these genes has revealed that the process of programmed cell death is evolutionarily conserved and has shed light on the molecular nature of the apoptotic machinery.

Animals↗
PubMed2001

Growth control: invertebrate insulin surprises!

Recent work on Drosophila has provided new insights into how insulin signalling - conserved in mammals, flies and worms - regulates growth and cell division during development. Invertebrates have been found to possess more insulin-like ligands than predicted, some of which behave as receptor antagonists.

Animals↗
PubMed2003

Spatial profiling invertebrate ganglia using MALDI MS.

The ability of MALDI TOF MS to spatially map peptides and proteins directly from a tissue is an exciting advance to imaging mass spectrometry. Recent advances in instrumentation for MS have resulted in instruments capable of achieving several micron spatial resolution while acquiring high-resolution mass spectra. Currently, the ability to obtain high quality mass spectrometric images depends on sample preparation protocols that often result in limited spatial resolution. A number of sample preparation and matrix deposition protocols are evaluated for spatial profiling of Aplysia californica exocrine gland and neuronal tissues. Such samples are different from mammalian tissues, but make good targets for method optimization because of the wealth of biochemical information available on neuropeptide processing and distribution. Electrospray matrix deposition and a variety of freezing methods have been found to be optimum for these invertebrate tissues, with the exact protocols being tissue dependent.

Animals↗
PubMed2003

Biology and pathology of interactions between fungi and invertebrates.

Having started this review with Di Bassi's work on a fungus destroying the French silkworm industry 160 years ago, the article finishes with a fungus being rendered more pathogenic through genetic engineering to kill an invertebrate. Yet, even while using a fungus as a biological weapon, one needs to be careful not to gun down innocent civilian targets alongside the enemy! It may be argued that this article will have little or no immediate clinical significance for the veterinarian involved in exotic species. And yet it is hoped that it will have provided an interesting and informative (not to say exotic!) introduction to the important area of mycotic disease in exotic species.

Animals↗
PubMed2003

Oral biology and disease in invertebrates.

It is hoped that this article has shown some of the amazing breadth of research into invertebrate mouthpart anatomy, development and pathology, and its relation to important disease processes that impinge on fields as diverse as environmental toxicology and antimalarial therapeutics, while also highlighting the need for further study in this field.

Animals↗
PubMed2001

Invertebrate anesthesia.

One hundred years ago (January 5th, 1901), an article in the Veterinary Record declared: The use of chloroform by practitioners is now common, and the amount of pain and suffering prevented is enormous. By its aid we are enabled to perform operations with success which without it were seldom satisfactory. A century later, in an age of sophisticated veterinary medicine, those words seem quaint, a relic of a bygone age. Our understanding of anesthesia of invertebrates in 2000 is very much at a comparable stage, however, and a great deal of research is needed to remedy this situation.

Anesthesia↗
PubMed1999

Sample taking in invertebrate veterinary medicine.

Invertebrates are important as pets of the 1990s but more so from economic, pest, and conservation perspectives. Since diagnosis by clinical examination is often taxing in these species, sample taking provides valuable insight into disease processes. Infection and parasitic diseases can be diagnosed by techniques from simple microscopy through to polymerase chain reaction technology. Cytology, hematology, and clinical chemistry, although not widely practiced, can provide critical baseline data in a disease investigation.

Aedes↗
PubMed1998

Emergency care of invertebrates.

Invertebrates are of increasing importance to the veterinary profession, but little scientifically-based information exists on their emergency care. Therefore, basic principles--supportive care, including administration of fluids, and specific therapy (where available)--must be followed up on. Knowledge and understanding of the biology and natural history of these animals are essential if critical care is to prove successful.

Animal Diseases↗
PubMed2001

Screening for carbon-bound phosphorus in marine animals by high-resolution 31P-NMR spectroscopy: coastal and hydrothermal vent invertebrates.

Animals of hydrothermal vents live in a unique environment that conceivably could lead to modifications of the usual phosphorus functional groups of importance in living systems. To explore this possibility, specimens of a sea anemone (unidentified) from the TAG hydrothermal field, Mid-Atlantic Ridge, the mussel Bathymodiolus N. sp. from the Mid-Atlantic Ridge, and the tubeworm Riftia pachyptila from the East Pacific Rise were analyzed for compounds containing the carbon&z.sbnd;phosphorus bond. The analysis was based on the use of 31P-nuclear magnetic resonance, which gives signals for C-P compounds that are well separated from those of biological phosphoric acid derivatives. The animals were extracted to provide a lipid- and a water-soluble fraction, leaving an insoluble, largely proteinaceous solid residue. The lipid and residue fractions were subjected to hydrolysis to release bound forms of phosphonic acids. All fractions were analyzed by 31P-NMR. Aminophosphonic acids [primarily NH2CH2CH2PO(OH)2 (1) and CH3NHCH2CH2PO(OH)2 (2)] represented the only type of C-P compound detected. These are well-known constituents of coastal invertebrates. For the mussel and sea anemone, these compounds were present in bound form in both the lipid and insoluble residue. The tube worm contained C-P material only in the insoluble residue, but in quite small amounts. The 31P-NMR method is especially valuable in being able to discriminate between compounds 1 and 2. By this technique, two coastal sea anemones (Tealia felina and Bunadosoma cavernata), previously thought to have 1 as the dominant aminophosphonic acid, were in fact found to be much richer in originally undetected 2. This compound was also detected for the first time in a mussel (Genkensia demissa).

Animals↗