1,721,027 research outputs found
Carnivores from Arena Cave: Pleistocene predators’ tales from Sicily
Full text linkThe Pleistocene site of Arena Cave (Baida, Palermo) represents one of the least studied
mammal assemblages from Sicily. It is a fissure-filling deposit, currently threatened by the
instability of an abandoned quarry front. Preliminary descriptions of its faunal content,
provided by Fabiani (1928) and confirmed by Vaufrey (1929), report the presence of four
iconic European Pleistocene carnivorous taxa: Canis lupus, Crocuta crocuta spelaea,
Panthera spelaea spelaea, and Ursus arctos. Although no stratigraphic data are available,
the biostratigraphic framework suggests a wide chronological range: from the Early-Middle
Pleistocene (Palaeoloxodon falconeri F.C.) and Late-Middle Pleistocene (Palaeoloxodon
mnaidriensis F.C.) to the Late Pleistocene (San Teodoro-Pianetti F.C.), Late Glacial
(Castello F.C.), and even the Holocene. It is therefore plausible that the assemblage
represents a mixed accumulation of faunal remains from different phases, which makes the
site particularly valuable for understanding the evolutionary pathways of Sicilian mammal
communities across the Pleistocene-Holocene transition. This study aims to fill a gap in our
knowledge of the palaeobiology of Pleistocene Sicilian carnivores, which has never been
systematically investigated at Arena Cave. Specifically, we estimated the body mass of each
predator (C. lupus, C. crocuta spelaea, Panthera s. spelaea) and assessed potential
ecological interactions within the carnivore guild. Our methodological framework combines
morphometric analyses with theoretical ecological models - Prey Focus Mass (PFM) and
Prey Mass Spectrum (PMS) - and incorporates the calculation of competition indices (CIs)
to assess niche overlap and infer predator guild structure (Hemmer, 2004; Hertler & Volmer,
2008). Our results offer new insights into the palaeobiology and trophic ecology of Sicilian
Pleistocene carnivores, contributing to a broader understanding of predator guild dynamics
in island ecosystems
Hyenas of Ice Age Sicily: Morphometric and biomechanical perspectives
Full text linkThe cave hyena (Crocuta crocuta spelaea) was among the most widespread and ecologically successful carnivores in Pleistocene Europe. Today, its closest extant relative,
the spotted hyena (C. crocuta), is confined to sub-Saharan Africa (Kruuk, 1972). Recent
paleogenetic studies indicate an early divergence between African and Eurasian Crocuta
(~2.5 Ma), followed by episodes of gene flow between lineages (Westbury et al., 2020). The dispersal of this genus towards the European continent occurred during the early phase of the Middle Pleistocene (Iannucci et al., 2021), with subsequent colonization of the Italian peninsula (Sardella & Petrucci, 2012). In Sicily, the cave hyena has been found in fossil associations attributed to the Palaeoloxodon mnaidriensis Faunal Complex - dated to the late Middle Pleistocene - and the San Teodoro-Pianetti Faunal Complex - dated to the late Pleistocene (Bonfiglio et al., 2003). This study investigates morphometric and functional variation in three Sicilian cave hyena populations from San Teodoro, Arena, and Zá Minica caves. We conducted a comparative morphometric analysis focusing on dental proportions (M1, P4) and a mandibular biomechanical analysis using cross-sectional geometry (Therrien 2005a, 2005b). Additionally, body mass was estimated for the studied populations using multiple skeletal parameters. The aim is to assess patterns of phenotypic differentiation among insular populations and to provide new insights into the evolutionary history of C. crocuta spelaea in Sicily
EVOLUTION, ADAPTATION AND IMMUNE FUNCTIONS OF FISH LECTINS
No full textFish are equipped with a complex lectin repertoire that,
like mammals, are involved almost all the
immune reactions.
Carbohydrate recognition and interactions mediated by
lectins have been recognized involved in vertebrate innate
immunity, not only for recognition of potential pathogens, but
also acting in the agglutination, immobilization and other
functional steps. In fish, C, F types galectins, Rhamnose-bind-
ing lectin (RBL) and pentraxin have been identified in both car-
tilaginous and bony fish.
In addition, selectins and other genes
have been found in the currently available fish
genomes. On the basis of our results about F-type and RBL
lectins we showed that: lectin repertoires in fish are highly
diversified and include not only representatives of the lectin
families; described in mammals, but also members of lectin
families described for the first time in fish species like the F
type lectins and RBL; RBL and FTL have been identified in the
eggs and embryos but they are also present in the serum. The
characterization indicates that the tissue-specific expression
and localization of the diverse lectin repertoires and their
molecular partners is consistent with their distinct biological
roles in innate and adaptive immunity; Therefore, in order to
identify trends linked to cold adaptation in
antarctic fish, we try, to compare Perciformes and the Antartic fish
Trematomus bernacchii F lectins propertie
Marine Mammal Immunity Toward Environmental Challenges
No full textHuman activities influence contaminant concentrations in aquatic organisms. It is increasingly common to monitor the marine environment and establish geographic trends of pollution by measuring contaminant levels in animals from higher trophic levels. Marine mammals are considered an ideal model for the assessment of immunological responses to pathogens and contaminants. In fact, living their entire life (or most of it) in the sea, they act as integrators of the stressors present in the marine environment. Marine mammals may have the potential to predict contaminant effects on health, and to be indicators of the status of the marine ecosystem. The impact of infection and environmental stress is here described through the analysis of the immunological processes based on large scale genomic approaches, highly informative of the interaction of genetic, disease and environmental factors.Human activities influence contaminant concentrations in aquatic organisms. It is increasingly common to monitor the marine environment and establish geographic trends of pollution by measuring contaminant levels in animals from higher trophic levels. Marine mammals are considered to be an ideal model for the assessment of immunological responses to pathogens and contaminants. In fact, living their entire lives (or most of it) in the sea, they act as integrators of the stressors present in the marine environment. Marine mammals may have the potential to predict contaminant effects on health and to be indicators of the status of the marine ecosystem. The impact of infection and environmental stress is here described through the analysis of the immunological processes based on large-scale genomic approaches, highly informative of the interaction of genetic, disease, and environmental factors
Ciliate Pheromones: Primordial Self-/Nonself-Recognition Signals
No full textAs is common among multicellular life forms, single-cell organisms also use pheromones to communicate among members of the same species. In protist ciliates, pheromones have been identified in functional association with mating systems. Consistent with this association, they have been regarded only as nonself-signals committed to eliciting a mating response of cells to which they bind in paracrine-like (heterologous) fashion. However, their spectrum of activity has revealed wider borders. It also includes a self-activity, which promotes the vegetative growth of the same cells from which pheromones are secreted and to which they continuously bind in autocrine fashion. This double self- and nonself-activity is made possible by the pheromones’ ability to compete with one another in cell-binding reactions. In the Euplotes species, which synthesizes pheromone families under the control of multiple series of alleles at a single locus, this ability is ensured by the relationships of the structural homology that link these molecules into species-specific globular, disulfide-rich protein families having a common three-helix fold
Identification of CPE and GAIT elements in 3’UTR of macrophage migration inhibitory factor (MIF) involved in inflammatory response induced by LPS in Ciona robusta
No full textInnate immune responses face infectious microorganisms by inducing inflammatory responses. Multiple genes
within distinct functional categories are coordinately and temporally regulated by transcriptional ‘on’ and ‘off’
switches that account for the specificity of gene expression in response to external stimuli. Mechanisms that
control transcriptional and post-transcriptional regulation are important in coordinating the initiation and resolution
of inflammation. Macrophage migration inhibitory factor (MIF) is an important cytokine that, in Ciona
robusta, is related to inflammatory response. It is well known that in C. robusta, formerly known as Ciona intestinalis,
the pharynx is involved in the inflammatory reaction induced by lipopolysaccharide (LPS) injection in
the body wall. Using this biological system, we describe the identification of two C. robusta MIFs (CrMIF1 and
CrMIF2). The phylogenetic tree and modeling support a close relationship with vertebrate MIF family members.
CrMIF1 and CrMIF2 possess two evolutionally conserved catalytic sites: a tautomerase and an oxidoreductase
site with a conserved CXXC motif. Real-time PCR analysis shows a prompt expression induced by LPS inoculation
in CrMIF1 and a late upregulation of CrMIF2 and in silico analyses of 3’UTR show a cis-acting GAIT element and a
CPE element in 3’-UTR, which are not present in the 3’-UTR of CrMIF1, suggesting that different transcriptional
and post-transcriptional control mechanisms are involved in the regulation of gene expression of MIF during
inflammatory response in C. robusta
INFLAMMATION AND TENTACLE REGENERATION RESPONSES IN ANEMONIA VIRIDIS (ANTHOZOA, CNIDARIA)
No full textMETHYLMERCURY EFFECTS ON Mytilus galloprovincialis HAEMOCYTES ACTIVITY
No full textBivalves, filter-feeding organisms, due to their wide distri-bution, are used by many countries in biomonitoring, particu-larly in the assessment of xenobiotics in the marine ecosystem.These sentinel organisms are able to accumulate trace metalsand other substances in their tissues. Haemocytes are effectorsof cellular immunity in bivalves and are capable of respond-ing to stressors through activities such as phagocytosis or cyto-toxicity. In order to identify cellular markers to investigate pol-lution, the effect of different concentrations of organic mercury(CH3HgCl) on the morphology and responses of Mytilus gal-loprovincialishaemocytes was studied in this work. Sublethalconcentrations of methylmercury, as evidenced by the Trypanblue exclusion test, were used to investigate its effect on mor-phology, the efficiency of phagocytosis towards yeast cells,the maintenance of the lysosomal membrane and the ability torelease cytotoxic molecules. Alterations in haemocyte viabili-ty, morphological changes and alterations in the cytoskeletonwere observed. The spreading ability, a cell morphometricparameter, was also used as an additional method. Exposureto CH3HgCl influenced the percentage and index of phagocy-tosis. Finally, cytoskeletal and morphological modificationslead to a reduction in the ability to adhere to the substrate andincorporate the target. The cytotoxic activity of M. gallo-provincialis haemocytes towards erythrocytes and the activityrevealed from lysis plaque assay has not been modified byadequate concentrations of methylmercury in the medium. Inaddition, membrane permeability could be affected bymethylmercury due to the reduced retention capacity of neu-tral red by the cells. This evidence confirms that theMediterranean mussel M. galloprovincialisis a suitable modelorganism in the study of the state of health of the marine envi-ronment and in particular for investigation of pollution causedby xenobiotics
EFFECTS OF THE ENRICHED-ORGANIC DIETS COMPOSITION ON EUROPEAN SEA BASS (Dicentrarchus labrax) NEW TOOLS FOR FISH WELFARE EVALUATION IN AQUACULTURE
No full textIn recent years, concern for the welfare of animals, including fish, has a strong impact on public opinion, putting pressure not only on producers and the scientific community, but also on institution to guarantee adequate "standards” for animal welfare. The market today challenges the production capacity of aquaculture by asking for products with consistently high quality. Unlike other farming methods, there is a lack of scientific information on the welfare of fish reared under intensive aquaculture conditions. Among the various aspects that characterize aquaculture, the increase in fish welfare has an impact on public opinion also for economic reasons whereby is very important to keep animals in good health, determine a higher feed conversion rate, lower mortality, optimal growth rate and high quality of the animal raised. Whereas stress events, acute and chronic, are reflected on the flesh, due to the increase in muscle activity (generally associated with this condition). We have firstly demonstrated that accelerometer tags are useful tools for welfare monitoring, indeed they do not affect welfare and health of implanted fish and that tagged fish can be sampled during experiments and be considered as representative of population, by displaying similar growth and physiological parameters compared to untagged fish. Consequently, the purpose of this study is to investigate the effect of two organic diets (contain organic vegetables and a natural antioxidant compound) on the welfare of the European sea bass compared to one conventional. A holistic approach was adopted, including the measurement of the primary stress response (cortisol), secondary (i.e. lactate, glucose, haematological parameters, lysozyme) and tertiary (i.e. swimming performance, muscle activity and growth parameters) indicators. In parallel, we evaluated the enzymatic activities of 7-ethoxyresoruphine-O-deethylase and glutathione-S-transferase, as index of function of the microsomal hepatic system of mixed function oxygenase (MFO), to evaluate the possible effects of pollutant contamination through the diet. In this study, multiparameter analysis approaches were performed to bring a better understanding of the effectiveness of a holistic approach to quantify welfare in organic aquaculture. The multi-parameter approach has outlined a complete picture of the physiological state of the sea bass. The Principal Component Analysis and the Multi-Criteria-Decision-Analysis have proved to be useful tools for an integrated assessment of the well-being of the fish, highlighting that the best condition was achieved in the experimental group fed with the organic protein-rich diet
- …
