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The pen shell Pinna nobilis (Linnaeus, 1758) is the largest endemic bivalve mollusc of the Mediterranean Sea, listed as an endangered species in the European Union. Because no information is available about the adaptation of pen shells to different habitats, herein the fundamental conditions of adaptation of P. nobilis to peculiar natural environments, such as the Strait of Messina (SM) and the meromictic Faro Lake (FL; Sicily, Italy), were explored by assessing the morphology, mucous production, osmoregulation and neurotransmission of their gills. Although gills of the pen shells from both sites exhibited a regular morphology, a higher presence of acid mucous cells was detected in P. nobilis from FL than SM, as well as higher levels of osmolytes but without interfering the osmoregulatory processes. About the functioning of gills, the cholinergic (i.e. acetylcholine and AChE) neuronal system was unaltered between individuals from the two sites, whereas the GABAergic neurotransmission (i.e. 4-aminobutyrate or GABA) was significantly augmented in gills of P. nobilis from FL than SM. This may be an adaptive response to hypoxic conditions in FL, as supported by the increased hypoxia-inducible factor (HIF-1α) in gills of pen shells from FL than SM. Noteworthy, this study reports for the first time the presence of the GABA neurotransmitter within the metabolite profile, obtained by application of a protonic Nuclear Magnetic Resonance (1H NMR)-based metabolomics approach, of a marine bivalve. Therefore, GABA may be suggested as a metabolite biomarker in pen shells. Overall, findings from this study provide new insights on the behavioural and adaptive responses of the pen shell Pinna nobilis settled in different peculiar environments. [ABSTRACT FROM AUTHOR]

Lake Faro (Sicily, Italy) is a natural confined brackish environment particularly subject to anthropogenic impact, resulting in a mixture of xenobiotic substances, i.e. heavy metals and polycyclic aromatic hydrocarbons (PAHs), and characterised by low hydrodynamics. In order to assess the water quality status of this pond, a multi-biomarker approach was applied on musselMytilus galloprovincialis(Lamarck, 1819) both inhabiting the lake and from a control site (Goro). Different biomarkers were investigated on mussel digestive glands and gills, including biomarkers of exposure (cytochrome P450 4, CYP4), neurotoxicity (acetylcholinesterase, AChE; choline acetyltransferase, ChAT), general stress (lysosomal membrane stability, LMS), and genotoxicity (micronucleus and comet assays). The results suggest significant responses related to the selected area. A statistically significant inhibition (P < 0.0001) of CYP4 in the digestive gland, and of AChE and ChAT in the gills, was found in specimens collected from Faro compared with the control. The lysosomal membrane stability of mussels from Lake Faro was lower than the reference site, while the DNA damages were significantly higher in mussels from the brackish area compared to the control. This study represents the first time the quality status of Lake Faro is assessed using a multi-biomarker approach on the musselM. galloprovincialis, which proved to be suitable to identify the effects of environmental pollutants at molecular and cellular levels. [ABSTRACT FROM PUBLISHER]

We investigated the haemolytic capacity of the crude venom extracted from isolated nematocysts ofPelagia noctiluca(Cnidaria: Scyphozoa), and evidenced the proteic fractions responsible for this activity. The nematocyst venom was used at various concentrations to evaluate the haemolytic activity and the lysosomal membrane stability of red blood cells of two teleostean species treated with the extract. The nematocyst extract was assayed against erythrocytes of the two teleostean species living in different environments,Carassius auratusas a common freshwater species, andLiza aurataas a representative of seawater species. Experiments on the haemolytic activity ofP. noctilucain the presence of lipid components of erythrocyte membranes showed that sphyngomyelin strongly inhibited this activity. The crude venom was analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis SDS-PAGE and high performance liquid chromatography (HPLC) to detect the proteic composition, and it was found that the active haemolytic components of this venom are distributed in at least four protein fractions. The results of our experiments indicated thatPelagia noctilucavenom induces haemolysis and lysosomal membrane destabilisation in both species and thatCarassius auratuswas more susceptible to jellyfish venom than wasLiza aurata. No significant differences in glutathione (GSH) levels were observed between control and treatments; consequently the toxins do not cause the oxidative stress but likely recognize specific targets (i.e. sphyngomyelin) in the plasmatic membrane of red blood cells. [ABSTRACT FROM PUBLISHER]

The present study was conducted to assess the toxicity of Foroozan (Iranian crude oil) on the ornate wrasse Thalassoma pavo (Labridae) using three sub-lethal crude oil concentrations. Gills, selected as target organ being the major route of hydrocarbon uptake, were excised after 48, 96 and 192 hours and analyzed by light and both scanning and transmission electron microscopy. Cellular biomarkers of exposure and/or effect were measured in branchial tissues of T. pavo, and severe lesions such as necrosis, aneurysms and disorganization of the lamellae proportional to the Foroozan exposure periods and concentrations were observed. The main alteration was on the lamellar epithelium, which displayed an irregular profile characterized by pavement cell cytoplasmic protrusion and an alteration of the oxygen chemosensing cells, resulting in impairment of various biological activities. Nevertheless, the ability of specimens to regulate calcium homeostasis and neurotransmission, as well as balance cell turnover, suggests that the species tested to not only survive but also recover in such high crude oil dosage regimen. The identification in gills of histological and neurological changes associated with acute crude oil exposure confirms the utility of the sub-lethal toxicity tests. [ABSTRACT FROM AUTHOR]

The pituitary gland of swordfish (Xiphias gladius L.) was studied immunohistochemically using antibodies against h-FSH β, h-LH β, GTH I β and GTH II β. The immunogold method for detection, at the ultrastructural level, of gonadotropins was also used. The immunostaining methods allowed identification of two distinct GTH I β (FSH-like) and GTH II β (LH-like) cells. Both GTH I β and GTH II β immunoreactive cells were observed in swordfish, although there were greater numbers of GTH II β immunoreactive cells. The localization and structure of the two different gonadotropic cells of swordfish are compared with other teleost arrangement. mRNA was isolated from X. gladius pituitaries and a series of oligonucleotides were constructed and used as primers in the polymerase chain reaction (PCR) to amplify GTH cDNAs. PCR products of eight independent PCR amplification reactions were cloned and sequenced for both GTH I β and GTH II β to avoid potential errors introduced during the PCR amplification. Two oligonucleotide probes were constructed and used in direct label fluorescence in situ hybridization (FISH) for measuring GTH I and GTH II mRNA expression. [ABSTRACT FROM AUTHOR]

Gill morphology and ultrastructure are described for Triturus carnifex and Salamandrina terdigitata with emphasis on differences occurring between two species that inhabit different aquatic biotopes. The morphology and ultrastructure have been studied using light microscopy and both scanning and transmission electron microscopy. The general organization of the gills is similar in the two species and shows the characteristics of Urodela larvae in which the gills consist of three tufts of filaments supported by gill arches III, IV and V. However, some differences are noticeable in the length of the main filament and in the number of secondary lamellae: in T. carnifex, a pond-dwelling salamander, the main filaments are long and rich in secondary lamellae; in the stream-type larva of S. terdigitata, the main filaments are shorter and show a lower number of secondary lamellae, located in its proximal portion. The cellular composition of the gill filament and of respiratory lamellae is different in S. terdigitata: in the gill filament basal cells, pavement cells, ciliated cells, club-shaped cells, mitochondria rich cells (MRCs) and Leydig cells have been recognized, while in the secondary lamellae the last cellular type does not appear. On the contrary, in T. carnifex we observe the same cellular composition in both filament and secondary lamellae. [ABSTRACT FROM AUTHOR]

A desktop laser-plasma double-stream gas-puff target soft X-ray (SXR) source, operating in the so-called "water window" spectral range (λ = 2.3–4.4 nm). was successfully employed to acquire 3D tomographic images in transmission mode, using a Fresnel zone-plate microscope. The microscope, operating at the He-like nitrogen spectral line, 2.88-nm wavelength, allows acquiring 3D SXR volumetric reconstructions with a resolution of a few microns. The development of a compact system offers the possibility to obtain 3D reconstructed images in relatively short time and in a laboratory environment, without the involvement of large "photon facilities", such as synchrotrons or free electron lasers, however, with the modest volume resolution at this point. The possibility to obtain three-dimensional images in the SXR wavelength range using a compact, laser-plasma based system may be useful for material and life sciences, where it is required to visualize small features of the samples in 3D that are not visible with a single 2D image. Details about the equipment and the setup constructions as well as some imaged samples will be presented and discussed. [ABSTRACT FROM AUTHOR]