Search results for "Mytilus"

Functional differential hemocytes behaviour in the clearance of bacteria and humoral defense factors variability in Mytilus galloprovincialis

2010

Gene expression specificity of the mussel antifungal mytimycin (MytM)

2011

Abstract We previously reported the nucleotide sequences and diversity of mytimycin (MytM) from the Mediterranean mussel, Mytilus galloprovincialis. Using real-time PCR (q-PCR), we observed that the MytM gene was mainly expressed in circulating hemocytes and to a less extent in the mantle. In vivo challenge with bacteria or with the yeast, Candida albicans, did not increase the expression as measured by q-PCR in hemocytes. By contrast, injection of the filamentous fungus, Fusarium oxysporum, induced a sudden and strong increase of expression at 9h p.i. (stimulation index of 25.7 ± 2.1). Optimum stimulating dose was 104 spores of F. oxysporum per mussel. In the same samples, AMP mytilin and …

Polymorphism of mytilin B mRNA is not traslated into mature peptide

2008

Diversity of mRNAs from mytilin B, one of the five mytilins identified in the Mediterranean mussel, Mytilus galloprovincialis, has been investigated from circulating hemocytes. One mussel expressed simultaneously two to ten different mytilin B mRNAs as observed in denaturing gradient gel electrophoresis (DGGE), defining 10 individual DGGE patterns (named A to J) within the mussels from Messina, Sicily (Italy). Three patterns accounted for 79% of the individuals whereas other patterns were found in only 2-7% of the 57 analyzed mussels. Base mutations were observed at specific locations, mainly within COOH-terminus and 3'UTR, leading to 36 nucleotide sequence variants and 21 different coding …

Activation of MAP kinase signaling pathway in the mussel Mytilus galloprovincialis as biomarker of environmental pollution

2010

Stimulation of MAP kinase signal transduction pathway by various stressful stimuli was investigated in the marine bivalve Mytilus galloprovincialis. Analyses were performed in animals exposed in laboratory to selected pollutants and in mussels collected in winter and summer along the eastern Adriatic coast (Croatia). Effects of oxidative stress, induced by tributyltin, hydrogen peroxide and water soluble fraction of diesel fuel on the activation/phosphorylation of the three Mitogen-Activated Protein Kinases (MAPKs) p38, JNK and ERK using a newly developed ELISA procedure were evaluated. MAP kinase activation was analyzed 1 h after exposure of mussels to chemical agents, and after recovery p…

A new lessepsian species in the western Mediterranean ( Brachidontes pharaonis Bivalvia: Mytilidae): density, resource allocation and biomass

2008

The present study reports on population dynamics and growth performance relative to a lesser known exotic invasive species ( Brachidontes pharaonis ) inhabiting the southern Mediterranean. The study was carried out in western Sicily, where B. pharaonis is present on both the submerged and emerged surfaces of a hyperhaline saltpan. Individuals were scraped, counted and measured for shell length, total weight, somatic, gonadic and shell biomass. Brachidontes pharaonis intensively colonized all hard substrates of the saltpan with annual average densities of 375 ± 293 ind. 400 cm −2 with density peaks in autumn as a function of habitat. The occurrence of juveniles was different for mediolittora…

The carrying capacity for Mediterranean bivalve suspension feeders: evidence from analysis of food availability and hydrodynamics and their integrati…

2004

Abstract In order to assess the carrying capacity of two Mediterranean areas, the Incze et al. model and its modification were applied. Our measures were carried out in the Gulf of Gaeta (Central MED), where mussels ( Mytilus galloprovincialis ) are intensively cultivated (production of approximately 200 t per year) and the Gulf of Castellammare (Southern MED), where bivalve culture is not widely practised. Velocities of water current and in field filtration rates were measured in each area. Total suspended matter (TSM), suspended chlorophyll-a (CHLa), lipid, protein and carbohydrate concentrations in the particulate were measured seasonally and used as tools to evaluate the trophic status …

Effects of acoustic stimulation on biochemical parameters in the digestive gland of Mediterranean mussel Mytilus galloprovincialis (Lamarck, 1819)

2020

Underwater sounds generated by anthropogenic activity can cause behavior changes, temporary loss of hearing, damage to parts of the body, or death in a number of marine organisms and can also affect healing and survival. In this study, the authors examined the effects of high-frequency acoustic stimulations on a number of biochemical parameters in the Mediterranean mussel, Mytilus galloprovincialis. During the experiment, animals were placed in a test tank and exposed to acoustic signals [a linear sweep ranging from 100 to 200 kHz and lasting 1 s, with a sound pressure level range of between 145 and 160 dBrms (re 1μParms)] for 3 h. Total haemocyte count was assessed and glucose levels, cyto…

Oxygen and carbon stable isotopes ofMytilus galloprovincialisLamarck, 1819 shells as environmental and provenance proxies

2019

Mollusc shell stable isotopes are commonly used to reconstruct past environmental conditions. However, despite being abundant components of natural and anthropogenic fossil accumulations, the geochemical composition of mussel shells ( Mytilus spp.) has rarely received attention in palaeoenvironmental studies. This study tests the suitability of oxygen isotopes (δ18Os) of Mytilus galloprovincialis as palaeothermometer. For 1 year, mussels and water samples were collected twice a month from Berria Beach, in Northern Spain. The geochemical data of the shells indicate that water temperatures can be reconstructed with an average offset of 1.2 ± 0.7°C with respect to the measured values. Furtherm…

Individual variability of mytimycin gene expression in mussel

2012

The antifungal peptide mytimycin (MytM) is synthesized by hemocytes of the Mediterranean mussel, Mytilus galloprovincialis. In addition to sequence and gene structure diversities previously reported from pooled hemocytes, the present report focused on the expression of mytm gene in individual M. galloprovincialis, before and after challenge. Within untreated mussel, MytM mRNA was observed by ISH in about 42% of circulating hemocytes, characterized by large, diffuse nucleus. Injection with Fusarium oxysporum increased such percentage, but in only some of the mussels. Similarly, MytM gene expression increased after injection in only some of the mussels, as measured by qPCR. Responders and not…

Combining heat-transfer and energy budget models to predict thermal stress in Mediterranean intertidal mussels

2011

Recent studies have emphasised that organisms can experience physiological stress well within their geographic range limits. Developing methods for mechanistically predicting the presence, absence and physiological performance of organisms is therefore important because of the ongoing effects of climate change. In this study, we merged a biophysical–ecological (BE) model that estimates the aquatic (high tide) and aerial (low tide) body temperatures of Mytilus galloprovincialis with a Dynamic Energy Budget (DEB) model to predict growth, reproduction and mortality of this Mediterranean mussel in both intertidal and subtidal environments. Using weather and chlorophyll-a data from three Mediter…