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PubMed2000

Invertebrate carcasses as a resource for competing Aedes albopictus and Aedes aegypti (Diptera: Culicidae).

Terrestrial invertebrate carcasses are an important resource for insects developing in pitcher plants. However, little is known of the role of these carcasses in other containers, which also receive leaf fall and stemflow inputs. This experiment investigated effects of accumulated invertebrate carcasses as a resource for two competing mosquitoes, Aedes albopictus (Skuse) and Aedes aegypti (L.), whether either species differentially benefited from accumulated carcasses, and if such a benefit affected interspecific competition. First, we measured accumulation of invertebrate carcasses in standard containers at a field site. We then used a replacement series with five different species ratios at the same total density, and varied the input of invertebrate carcasses [dead Drosophila melanogaster (Meigen) ] in three levels: none, the average input from our field site, or the maximum input recorded at our field site. Survivorship, development time, and mass were measured for each mosquito species as correlates of population growth, and were used to calculate a population performance index, lambda'. There were strong positive effects of invertebrate carcass additions on all growth correlates and lambda'. Differences in performance between species were pronounced in small or no carcass additions and absent in large inputs of invertebrate carcasses, but there was little evidence that inputs of invertebrate carcasses altered the competitive advantage in this system. These results suggest that terrestrial invertebrate carcasses may be an important resource for many types of container communities, and large accumulations of dead invertebrates may reduce resource competition between these mosquitoes, thus favoring coexistence. We propose that the total amount of resource, including accumulated invertebrate carcasses, may explain observed patterns of replacement involving these mosquitoes.

Aedes↗

PubMed1998

Invertebrates in testing of environmental chemicals: are they alternatives?

An enlarged interpretation of alternatives in toxicology testing includes the replacement of one animal species with another, preferably a nonmammalian species. This paper reviews the potential of invertebrates in testing environmental chemicals and provides evidence of their usefulness in alternative testing methodologies. The first part of this review addresses the use of invertebrates in laboratory toxicology testing. Problems in extrapolating results obtained in invertebrates to those obtained from vertebrates are noted, suggesting that invertebrates can essentially be used in addition to rather than as replacements for vertebrates in laboratory toxicity tests. However, evaluation of the ecologic impact of environmental chemicals must include defining end points that may frequently differ from those classically used in biomedical research. In this context, alternative approaches using invertebrates may be more pertinent. The second part of the review therefore focuses on the use of invertebrates in situ to assess the environmental impact of pollutants. Advantages of invertebrates in ecotoxicologic investigation are presented for their usefulness for seeking mechanistic links between effects occurring at the individual level and consequences for higher levels of biologic organization (e.g., population and community). In the end, it is considered that replacement of vertebrates by invertebrates in ecotoxicity testing is likely to become a reality when basic knowledge of metabolic, physiologic, and developmental patterns in the latter will be sufficient to assess the effect of a given chemical through end points that could be different between invertebrates and vertebrates.

Animal Testing Alternatives↗

PubMed2000

Biomarkers in terrestrial invertebrates for ecotoxicological soil risk assessment.

This review has served to present the most recent information on a selected series of biomarker studies undertaken on soil invertebrates during two extensive European-funded scientific consortia, BIOPRINT and BIOPRINT-II. The goals were to develop and validate methods for the analysis of markers of stress in a range of soil-dwelling organisms. We have discussed the potential and limitations of the following invertebrate biomarkers for soil risk assessment purposes: heat shock proteins, histological and ultrastructural markers, metallothioneins and metal-binding proteins, esterases, lysosomal integrity, and the novel biomarker histidine. The hsp response in soil invertebrates is especially suitable to indicate the effects of exposure to comparatively low concentrations for a range of toxicants and can be regarded as a biomarker of general stress. The application of MTs and other metal-binding proteins as biomarkers for exposure in soil invertebrates has been well described, and new methods are being developed for analyzing MT induction both at the protein and molecular level, and reliable and reproducible methods are now available. (Cd)-MT is well characterized for the springtails and its MT concentration is a useful biomarker for exposure as well as for effect. For snails, (Cd)-MT can accumulate in the midgut gland over extended periods of time and therefore its concentration is a biomarker not only for recent intoxication but also for events of cadmium exposure that snails may have experienced a long time before the measurement took place. Cellular and histological alterations can be regarded as reflecting the "health" state of a cell, which may be a measure for the presence of toxicants. Histopathological work on terrestrial invertebrates, however, is still scarce. Isozymes have been poorly studied in soil invertebrates despite their promising role as potential biomarkers in aquatic organisms. Among the large diversity of isozymes, the most well studied are esterases that are frequently used a biomarkers of exposure to various classes of pesticides. Many other isozymes offer potentials for biomarker research, such as glucosephosphate isomerase and phosphoglucomutase, both enzymes necessary for the glycolytic pathway. The lysosomal system has been identified as a particular target for the toxic effects of xenobiotics, although it has yet a limited application in soil invertebrates. This marker is nonspecific, responding equally sensitively to organic or inorganic contamination; however, if used in combination with an earthworm immnunocompetence assay such as total immunoactivity of the coelomocytes, then it is possible to be more specific as to the likely nature of contamination. Free histidine was positively correlated with increasing copper exposure and total copper burden in earthworms from a semifield study. Histidine may thus act as a biomarker of exposure. The transient responses and confounding factors of biomarkers obscure a proper interpretation of biomarker responses under field conditions. These factors are still very poorly understood and require more study. For risk assessment purposes it is recommended that the aforementioned biomarkers may show promise when included in a suite of biomarkers among different soil invertebrate species. It is recommended that a risk assessment protocol draw upon ranking of biomarker responses on a defined scale. It is also hoped that the problems outlined in this review will aid the direction of future research on soil invertebrate biomarkers.

Animals↗

PubMed2005

Significance of bacteria associated with invertebrates in drinking water distribution networks.

The implication of invertebrates found in drinking water distribution networks to public health is of concern to water utilities. Previous studies have shown that the bacteria associated with the invertebrates could be potentially pathogenic to humans. This study investigated the level and identity of bacteria commonly associated with invertebrates collected from the drinking water treatment systems as well as from the main pipelines leaving the treatment works. On all sampling occasions bacteria were isolated from the invertebrate samples collected. The highest bacterial counts were observed for the samples taken before filtration as was expected. There were, however, indications that optimal removal of invertebrates from water did not always occur. During the investigation, 116 colonies were sampled for further identification. The isolates represent several bacterial genera and species that are pathogenic or opportunistic pathogens of humans. Diarrhoea, meningitis, septicaemia and skin infections are among the diseases associated with these organisms. The estimated number of bacteria that could be associated with a single invertebrate (as based on average invertebrate numbers) could range from 10 to 4000 bacteria per organism. It can, therefore, be concluded that bacteria associated with invertebrates might under the worst case scenario pose a potential health risk to water users. In the light of the above findings it is clear that invertebrates in drinking water should be controlled at levels as low as technically and economically feasible.

Animals↗

PubMed2026

Novelty, diversity, and genetic dark matter in enterococci of invertebrates.

Enterococci appear to have originated in the guts of early terrestrializing arthropods and invertebrates over 425 million years ago-hosts that are now highly diverse and widespread in nature today. Yet most knowledge of the genus comes from human infection-associated lineages with genomes swollen by the recent accretion of foreign DNA conveyed by mobile elements. Because invertebrates dominate terrestrial animal diversity and biomass, they would be predicted to constitute a major but little-explored reservoir of enterococcal diversity. We therefore systematically examined Enterococcus association and species diversification in invertebrate hosts of the comparatively natural, isolated, but well-characterized environment of the Azorean island of Terceira. Over 100 invertebrate specimens were examined for associated enterococci, which were taxonomically classified by whole-genome sequencing. Supporting the existence of a large pool of uncharacterized enterococci and Enterococcus-adapted genes, 40% (eight of 20) of the Enterococcus species identified were either undescribed, including four candidate new species described here, or very recently discovered. In contrast, control isolates from vertebrates were exclusively of known species typical of sampling elsewhere, discounting geographic isolation as a main driver of the novelty observed. Further, because of the abundance of E. casseliflavus and E. flavescens in this collection, we obtained the resolution necessary to quantify the divergence and decipher the drivers of speciation in the controversial division between these naturally vancomycin-resistant species. These findings provide robust support for the existence of a large pool of new species and unexplored adaptive traits in invertebrate-associated enterococci-diverse environmental survival traits optimized for expression in an enterococcal background, and well positioned for transmission into human-associated enterococcal strains.IMPORTANCEEnterococci are auxotrophic gut-associated bacteria that co-evolved with their terrestrial hosts over many eons. In the last 75 years-the "antibiotic era"-E. faecalis and E. faecium gained genes for antibiotic resistance and enhanced virulence, emerging as leading causes of multidrug-resistant infection. Little is known about the source of those genes or the pathway by which they entered human-associated strains. A recent global survey suggested a potentially large repository of uncharacterized genetic diversity in the enterococci of invertebrates. We directly tested this prospect by examining enterococci of invertebrate hosts in a largely natural and pastoral environment. Our findings provide clear evidence that invertebrates naturally harbor vast unexplored enterococcal diversity. Moreover, associations are likely driven by intrinsic host selection factors rather than geographic isolation. This expands our knowledge of Enterococcus biodiversity, including the identification of four novel species, identifying a vast reservoir of enterococcal genes available to species that colonize and infect humans.

Animals↗

PubMed2007

Small is useful in endocrine disrupter assessment--four key recommendations for aquatic invertebrate research.

As we enter the 21st "biocentury", with issues such as biodiversity and biotechnology growing in public profile, it is important to reflect on the immense ecological, medical and economic importance of invertebrates. Efforts to understand the diverse biology of invertebrates come from many directions, including Nobel Prize winning developmental biology, research to control insects that threaten human health and food supplies, aquaculture opportunities and also within ecotoxicology. In the latter context, this special journal volume highlights the importance of addressing endocrine disruption in aquatic invertebrates, from molecular and cellular biomarkers to population-relevant adverse effects. The contributors to this special volume have provided an excellent assessment of both the fundamental endocrinology and applied ecotoxicology of many aquatic invertebrate groups. On the premise that reproductive success is ultimately the vital population parameter, this chapter gives a personal view of key gaps in knowledge in invertebrate reproductive and developmental endocrinology and ecotoxicology. Based on current knowledge, there are four key issues that need to be prioritised within aquatic ecotoxicology: (1) a wider assessment of the reproductive status of invertebrates in both freshwater and coastal ecosystems; (2) prioritisation of laboratory studies in OECD and other regulatory test organisms, including basic endocrinology and ADME (absorption, distribution, metabolism and excretion) research; (3) development and validation of mechanistic biomarkers that can be used as "signposts" to help prioritise species and chronic test endpoint selection, and help link data from laboratory and field studies; and (4) develop a comparative invertebrate toxicology database utilising the prioritised reference chemicals from the EDIETA workshop, encompassing the diverse modes-of-action pertinent to endocrine disrupter testing in both aquatic arthropod and non-arthropod invertebrates.

Animals↗

PubMed2006

Marine invertebrate cytochrome P450: emerging insights from vertebrate and insects analogies.

Cytochrome P450 enzymes (P450s) are responsible for the oxidative metabolism of a plethora of endogenous and exogenous substrates. P450s and associated activities have been demonstrated in numerous marine invertebrates belonging to the phyla Cnidaria, Annelida (Polychaeta), Mollusca, Arthropoda (Crustacea) and Echinodermata. P450s of marine invertebrates and vertebrates show considerable sequence divergence and the few orthologs reveal the selective constraint on physiologically significant enzymes. P450s are present in virtually all tissues of marine invertebrates, although high levels usually are found in hepatic-like organs and steroidogenic tissues. High-throughput technologies result in the rapid acquisition of new marine invertebrate P450 sequences; however, the understanding of their function is poor. Based on analogy to vertebrates and insects, it is likely that P450s play a pivotal role in the physiology of marine invertebrates by catalyzing the biosynthesis of signal molecules including steroids such as 20-hydroxyecdysone (the molting hormone of crustaceans). The metabolism of many exogenous compounds including benzo(a)pyrene (BaP), pyrene, ethoxyresorufin, ethoxycoumarin and aniline is mediated by P450 enzymes in tissues of marine invertebrates. P450 gene expression, protein levels and P450 mediated metabolism of xenobiotics are induced by PAHs in some marine invertebrate species. Thus, regulation of P450 enzyme activity may play a central role in the adaptation of animals to environmental pollutants. Emphasis should be put on the elucidation of the function and regulation of the ever-increasing number of marine invertebrate P450s.

Animals↗

PubMed2004

Sampling and quantifying invertebrates from drinking water distribution mains.

Water utilities in the Netherlands aim at controlling the multiplication of (micro-) organisms by distributing biologically stable water through biologically stable materials. Disinfectant residuals are absent or very low. To be able to assess invertebrate abundance, methods for sampling and quantifying these animals from distribution mains were optimised and evaluated. The presented method for collecting invertebrates consists of unidirectionally flushing a mains section with a flow rate of 1 ms(-1) and filtering the flushed water in two separate flows with 500 microm and 100 microm mesh plankton gauze filters. Removal efficiency from mains was evaluated in nine experiments by collecting the invertebrates removed from the mains section by intensive cleaning immediately subsequent to sampling. Of 12 taxa distinguished, all except case-building Chironomidae larvae (2%) and Oligochaeta (30%) were removed well (51-75%). Retention of invertebrates in 100 microm filters was evaluated by filtering 39 filtrates using 30 microm filters. Except for flexible and small invertebrates such as Turbellaria (13%), Nematoda (11%) and Copepoda larvae (24%), most taxa were well retained in the 100 microm filters (53-100%). During sample processing, the method for taking sub-samples with a 10 ml pipette from the suspension of samples with high sediment concentrations was found to perform well in 75% of the samples. During a 2-year national survey in the Netherlands and consecutive investigations, the method appeared to be very suitable to assess the abundance of most invertebrate taxa in drinking water distribution systems and to be practicable for relatively inexperienced sampling and lab technicians. Although the numbers of small, less abundant or sessile taxa were not accurately assessed using the method, these taxa probably should not be the primary focus of monitoring by water utilities, as consumer complaints are not likely to be caused by these invertebrates. The accuracy of quantifying small invertebrates was further improved, however, by filtering the 100microm filtrate with a 30microm mesh plankton gauze filter.

Animals↗

PubMed1999

Invertebrate integrins: structure, function, and evolution.

Integrins are a family of molecules that have fundamental roles in cell-cell and cell-matrix adhesion. It is thought that all metazoan cells have one or more integrin receptors on their surface and that these molecules may have been key in the evolution of multicellularity. Knowledge of the structure, function, and distribution of integrin subunits in invertebrate phyla remains incomplete. However, through the recent use of polymerase chain reaction, integrin subunits have been identified in at least five phyla; sponges, cnidarians, nemadodes, arthropods, and echinoderms. The structure of all of the invertebrate subunits is remarkably similar to that of vertebrate integrin subunits. Some experimental data and patterns of expression indicate that invertebrate integrins have a range of functions similar to those of vertebrate integrins. The ligands are not well characterized but at least two laminin-binding receptors have been identified and two other receptors appear to bind using Arg-Gly-Asp motifs. Invertebrate integrins are present during development, in adults, and on a range of cell types including cells with immunological functions such as hemocytes and coelomocytes. Analysis of the invertebrate beta subunits indicates that the invertebrate integrins have diverged independently within each phylum. The two major clades of vertebrate integrins (beta 1, beta 2, beta 7 and beta 3, beta 5, beta 6, beta 8) appear to have radiated since the divergence of the deuterostomes and there are no distinct orthologous subunits in any of the invertebrate phyla. Since fundamental functions of integrins appear to be conserved, studies of invertebrate integrins have the potential of contributing to our understanding of this important group of receptors.

Amino Acid Sequence↗

PubMed1985

Neuropeptide function: the invertebrate contribution.

The following is a list of generalizations that arise from considering the present state of knowledge concerning the functions of invertebrate peptides. Some of these clearly also apply to vertebrates. Invertebrate peptides can be classified into structurally related groups. Structural similarity of peptides may represent true evolutionary homology by selection acting on an original gene. Alternatively, independent evolution of similar genes may have occurred because certain amino acid sequences represent optimal solutions to complex functional problems. Invertebrate neuropeptides have multiple functions. Thus, proctolin is a cardioactive peptide, a skeletal neuromuscular transmitter, a hindgut neuropeptide, a peptide of CNS interneurons (Keshishian & O'Shea 1984) and may have humoral roles. Invertebrate peptides act through a variety of molecular mechanisms. Generalizations about the mechanism cannot yet be made. Thus, proctolin's action on crustacean skeletal muscle is not associated with stimulation of cyclic-AMP or protein phosphorylation, but the action of SCPB on molluscan skeletal muscle involves elevation of cAMP. Invertebrate peptide inactivation can be caused by proteolysis that can also function to enhance peptide bioactivity. Proctolin is made virtually biologically inactive by any proteolysis, but alpha-BCP bioactivity is enhanced by two steps of carboxy peptidase digestion before being functionally inactivated. Protease action on released peptides is not necessarily a "simple" form of transmitter inactivation. Protease action also involves functional processing whereby the temporal and spatial parameters of a peptide's action may be shaped. Invertebrate neuropeptides are frequently co-localized with other neuroeffectors. Peptides may be co-localized and released with other active peptides as in the bag-cell example, or may be coactive with more conventional transmitters, as in the Ds motoneuron example. In such circumstances there is no reason to view either transmitter as primary or secondary. Invertebrate neuropeptides are widely involved in the control of muscle contraction. These effects may be locally and directly mediated as in the Ds motoneuron example or may be humoral. The peptide may act directly on the muscle contractile system or function to modulate the muscles' response to other motor input. Muscle contraction may be induced by a neuropeptide without depolarization of the muscle cells, for example see proctolin. Invertebrate neuropeptides are frequently involved in the control of oscillatory functions. In several examples peptides activate rhythmic myogenic contractions of cardiac and skeletal muscle.(ABSTRACT TRUNCATED AT 400 WORDS)

Amino Acid Sequence↗

PubMed2005

Prostaglandins in non-insectan invertebrates: recent insights and unsolved problems.

Prostaglandins (PG) are oxygenated derivatives of C20 polyunsaturated fatty acids including arachidonic and eicosapentaenoic acids. In mammals, these compounds have been shown to play key roles in haemostasis, sleep-wake regulation, smooth muscle tone, and vaso-, temperature and immune regulation. In invertebrates, PGs have been reported to perform similar roles and are involved in the control of oogenesis and spermatogenesis, ion transport and defence. Although there is often a detailed understanding of the actions of these compounds in invertebrates such as insects, knowledge of their mechanism of biosynthesis is often lacking. This account provides a critical review of our current knowledge on the structure and modes of biosynthesis of PGs in invertebrates, with particular reference to aquatic invertebrates. It emphasises some of the most recent findings, which suggest that some PGs have been misidentified. Prostaglandins in invertebrates can be categorised into two main types; the classical forms, such as PGE2 and PGD2 that are found in mammals, and novel forms including clavulones, bromo- and iodo-vulones and various PGA2 and PGE2 esters. A significant number of reports of PG identification in invertebrates have relied upon methods such as enzyme immunoassay that do not have the necessary specificity to ensure the validity of the identification. For example, in the barnacle Balanus amphitrite, although there are PG-like compounds that bind to antibodies raised against PGE2, mass spectrometric analysis failed to confirm the presence of this and other classical PGs. Therefore, care should be taken in drawing conclusions about what PGs are formed in invertebrates without employing appropriate analytical methods. Finally, the recent publication of the Ciona genome should facilitate studies on the nature and mode of biosynthesis of PGs in this advanced deuterostomate invertebrate.

Animals↗

PubMed2003

Metabotropic histamine receptors--nothing for invertebrates?

Histamine, a major neurotransmitter both in vertebrates and invertebrates, transmits its actions through a set of well-known receptors. In vertebrates, these receptors belong to the family of G-protein-coupled receptors. In invertebrates, the few well-characterized actions of histamine are transmitted through ionotropic histamine receptors. To evaluate if metabotropic histamine receptors are part of the invertebrate histaminergic signaling cascade, I identified the complete set of metabotropic bioamine receptors from two invertebrates, whose entire genome has been sequenced: the fruitfly Drosophila melanogaster and the soil nematode Caenorhabditis elegans. A comparison with representatives of all groups of metabotropic bioamine receptors from vertebrates and invertebrates showed that none of these receptors clusters together with any of the four groups of vertebrate histamine receptors. This implies that no direct homologues to vertebrate metabotropic histamine receptor are present in invertebrates. Therefore, it is reasonable to account that the histaminergic neurotransmission in invertebrates is exclusively transmitted through ionotropic histamine receptors and that metabotropic histamine receptors evolved after the split between vertebrates and invertebrates.

Animals↗

PubMed2004

Evidence for endocrine disruption in invertebrates.

The issue of endocrine disruption (ED) in invertebrates has generated remarkably little interest in the past compared to research with aquatic vertebrates in this area. However, with more than 95% of all known species in the animal kingdom, invertebrates constitute a very important part of the global biodiversity with key species for the structure and function of aquatic and terrestrial ecosystems. Despite the fact that ED in invertebrates has been investigated on a smaller scale than in vertebrates, invertebrates provide some of the best documented examples for deleterious effects in wildlife populations following an exposure to endocrine-active substances. The article provides an overview of the diversity in endocrine systems of invertebrates. The principal susceptibility of invertebrates to endocrine-active compounds is demonstrated with the case studies of tributyltin effects in mollusks and of insect growth regulators, the latter as purposely synthesized endocrine disrupters. The additional evidence for ED in invertebrates from laboratory and field studies is summarized as an update and amendment of the EDIETA report from 1998. Finally, conclusions about the scale and implications of the observed effects are drawn and research needs are defined.

Animals↗

PubMed2004

The impact of the herbicide glyphosate on leaf litter invertebrates within Bitou bush, Chrysanthemoides monilifera ssp rotundata, infestations.

Chrysanthemoides monilifera ssp rotundata (L) T Norl (Bitou bush) is a serious environmental weed along the southeast coast of Australia. The herbicide glyphosate is commonly used to control C monilifera on the New South Wales coastline, but there have been few studies examining the effects of this herbicide on invertebrate communities in the field, especially on sand dunes. Control and impact sites were selected in coastal hind dunes heavily infested with C monilifera, and the impact sites were sprayed with a 1:100 v/v dilution of glyphosate-isopropyl 360 g AE litre(-1) SL (Roundup Biactive). Leaf litter invertebrates were sampled before spraying and after spraying by collecting fixed areas of leaf litter in both the control and impact sites. Samples were sorted for particular invertebrates involved in leaf litter decomposition and some of their predators. This study did not identify any significant direct or indirect effects on leaf litter invertebrate abundance or community composition in the four months following herbicide application. The litter invertebrate assemblages were highly variable on a small spatial scale, with abiotic factors more strongly regulating leaf litter invertebrate numbers than glyphosate application. These results conflict with previous studies, indicating that the detrimental indirect effects herbicide application has on non-target litter invertebrates may depend upon the application rate, the vegetation community and structure and post-spray weather.

Animals↗

PubMed2004

Invertebrate humoral factors: cytokines as mediators of cell survival.

The presence and the different functional aspects of cytokine-related molecules in invertebrates are described. Cytokine-like factors affect immune functions, such as cell motility, chemotaxis, phagocytosis and cytotoxicity. In particular, cell migration shows a species-specific effect for IL-1alpha and TNF-alpha and a dose-correlated effect for IL-8, PDGF-AB and TGF-beta1. Apart from some exceptions, the phagocytic effect increases significantly at all the concentrations tested and with all the species used. PDGF-AB, TGF-beta1 and IL-8 provoke conformational changes in mollusk immunocytes, involving the signaling transduction pathways of phosphatidylinositol and cAMP. PDGF-AB and TGF-beta1 partially inhibit the induced programmed cell death in an insect cell line, and the survival effect is mediated by the activation of phosphatidylinositol 3-kinase, PKA and PKC. The exogenous administration of these growth factors in an invertebrate wound repair model showed that they are able to control the wound environment and promote the repair process by accelerating the coordinated activities involved. Moreover, IL-1alpha, IL-2 and TNF-alpha are able to induce nitric oxide synthase. PDGF-AB and TGF-beta1 provoke an increase in neutral endopeptidase-24.11 (NEP)-like activity in membrane preparations from mollusk immunocytes, while NEP deactivates the PDGF-AB- and TGF-beta1-induced cell shape changes. Cytokines are also involved in invertebrate stress response in a manner extremely similar to that in vertebrates. Several studies suggest the existence on the mollusk immunocyte membrane of an ancestral receptor capable of binding both IL-2 and CRH. Furthermore, the competition found between CRH and a large number of cytokines supports the idea that invertebrate cytokine receptors show a certain degree of promiscuity. The multiple functions of cytokines detected in invertebrates underline another characteristic of mammalian cytokines, i.e. their great pleiotropicity. Altogether, the studies on the function of the invertebrate humoral factors show a close overlapping with those found in vertebrates, and the hypothesized missing correlation between invertebrate and vertebrate cytokine genes that is emerging from the limited molecular biology data present in literature might represent a very peculiar strategy followed by Nature in the evolution of cytokines.

Animals↗

PubMed1994

Invertebrates can tell us something about senescence.

Senescence is a ubiquitous phenomenon, i.e., all vertebrates and invertebrates will ultimately manifest it. Any attempt to answer the question of adaptive significance of the aging process must take into account the universality of and change in the DNA molecule that governs, integrates, regulates and ensures the vitality of all organisms. With invertebrates and from the comparative viewpoint, there are examples of: 1) rapid senescence and sudden death; 2) gradual senescence with definite life span; 3) negligible senescence; 4) genetic influence on life span, mortality rates, and age-related diseases. Although these characteristics are ascribed to invertebrates and vertebrates, this need not force upon invertebrates the organization, structure and eventual features of vertebrate senescence. "Invertebrate gerontologists" can thus, freely delve into certain unique aspects of what may be the more primitive mechanisms of aging in invertebrates. In contrast, using the opposite strategy that is still problematic, i.e., linking invertebrate and vertebrate aging, seems to give us an approach to universality that might eventually reveal more readily obvious and homologous kinship.

Aging↗

PubMed2001

On the existence of cytokines in invertebrates.

Based on the assumption that invertebrates, like vertebrates, possess factors regulating responses to infection or wounding, studies dealing with the evolution of immunity have focussed on the isolation and characterisation of putative cytokine-related molecules from invertebrates. Until recently, most of our knowledge of cytokine- and cytokine receptor-like molecules in invertebrates relies on functional assays and similarities at the physicochemical level. As such, a phylogenetic relationship between invertebrate cytokine-like molecules and vertebrate counterparts could not be convincingly demonstrated. Recent genomic sequence analyses of interleukin-1-receptor-related molecules, that is Toll-like receptors, and members of the transforming growth factor-beta superfamily suggest that the innate immune system of invertebrates and vertebrates evolved independently. In addition, data from protochordates and annelids suggest that invertebrate cytokine-like molecules and vertebrate factors do not have the same evolutionary origin. We propose instead that the convergence of function of invertebrate cytokine-like molecules and vertebrate counterparts involved in innate immune defences may be based on similar lectin-like activities.

Animals↗

PubMed2005

Leachability of protein and metals incorporated into aquatic invertebrates: are species and metals-exposure history important?

To partially simulate conditions in fish intestinal tracts, we leached six groups of metals-contaminated invertebrates at pH 2 and pH 7, and analyzed the concentrations of four metals (Cd, Cu, Pb, and Zn) and total protein in the leachates. Four of the groups of invertebrates were benthic macroinvertebrates collected from metals-contaminated rivers (the Clark Fork River in Montana and the Coeur d'Alene River in Idaho, USA); the other two groups of invertebrates (one of which was exposed to metals in the laboratory) were laboratory-reared brine shrimp (Artemia sp.). Additionally, we fractionated the pH 2 leachates using size-exclusion chromatography (SEC). Protein content was 1.3 to 1.4x higher in Artemia than in the benthic macroinvertebrates, and leachability of metals and protein differed considerably among several of the groups of invertebrates. In SEC fractions of the pH 2 leachates from both groups of Artemia, Cu and protein co-eluted; however, Cu and protein did not co-elute in SEC fractions of the leachates from any of the benthic macroinvertebrate groups. Although none of the other three metals co-eluted with protein in any of the pH 2 leachates, one or more of the metals co-eluted with lower-molecular-weight molecules in the leachates from all of the groups of invertebrates. These results suggest fundamental differences in metal-binding properties and protein leachability among some invertebrates. Thus, different invertebrates and different histories of metals exposure might lead to different availability of metals and protein to predators.

Animals↗