Search results for "Mollusk"
showing 10 items of 22 documents
Drivers of shell growth of the bivalve, Callista chione (L. 1758) - Combined it environmental and biological factors
2018
WOS:000426027100014; Seasonal shell growth patterns were analyzed using the stable oxygen and carbon isotope values of live-collected specimens of the bivalve Callista chione from two sites in the Adriatic Sea (Pag and Cetina, Croatia). Micromilling was performed on the shell surface of three shells per site and shell oxygen isotopes of the powder samples were measured. The timing and rate of seasonal shell growth was determined by aligning the delta O-18(shell)-derived temperatures so that the best fit was achieved with the instrumental temperature curve. According to the data, shells grew only at very low rates or not at all during the winter months, i.e., between January and March. Shell…
A new haemocyanin in cuttlefish (Sepia officinalis) eggs: sequence analysis and relevance during ontogeny
2014
Abstract Background Haemocyanin is the respiratory protein of most of the Mollusca. In cephalopods and gastropods at least two distinct isoforms are differentially expressed. However, their physiological purpose is unknown. For the common cuttlefish Sepia officinalis, three isoforms are known so far, whereas for only two of them the complete mRNA sequences are available. In this study, we sequenced the complete mRNA of the third haemocyanin isoform and measured the relative expression of all three isoforms during embryogenesis to reveal a potential ontogenetic relevance. Results The cDNA of isoform 3 clearly correlates to the known Sepia officinalis haemocyanin subunits consisting of eight …
Mollusk antimicrobial peptides A review from activity-based evidences to computer-assisted sequences
2011
Antimicrobial peptides (AMPs) represent the most universal immune effectors. Molluscs constitute the second largest animal phylum, after Arthropods, in term of number of species. Only a negligible number has been investigated regarding AMPs. The choice of the species to be studied relied on their economical importance and availability. First studies on molluscan AMPs dated from 1996 and were based on biological activities of biochemical-purified fractions. Such approach released all the original structures we know, with biological activity sometimes different from one isoform to another. Then, molecular biology techniques were applied to molluscan AMPs starting in 1999. Complete screening o…
Contrasting temperature responses in seasonal timing of cercariae shedding by Rhipidocotyle trematodes
2022
AbstractGlobal warming is likely to lengthen the seasonal duration of larval release by parasites. We exposed freshwater mussel hosts, Anodonta anatina, from 2 high-latitude populations to high, intermediate and low temperatures throughout the annual cercarial shedding period of the sympatric trematodes Rhipidocotyle fennica and R. campanula, sharing the same transmission pathway. At the individual host level, under warmer conditions, the timing of the cercarial release in both parasite species shifted towards seasonally earlier period while its duration did not change. At the host population level, evidence for the lengthening of larvae shedding period with warming was found for R. fennica…
Positive selection in development and growth rate regulation genes involved in species divergence of the genus Radix
2015
AbstractBackgroundLife history traits like developmental time, age and size at maturity are directly related to fitness in all organisms and play a major role in adaptive evolution and speciation processes. Comparative genomic or transcriptomic approaches to identify positively selected genes involved in species divergence can help to generate hypotheses on the driving forces behind speciation. Here we use a bottom-up approach to investigate this hypothesis by comparative analysis of orthologous transcripts of four closely related EuropeanRadixspecies.ResultsSnails of the genusRadixoccupy species specific distribution ranges with distinct climatic niches, indicating a potential for natural …
Marine Animal-Derived Compounds and Autophagy Modulation in Breast Cancer Cells
2021
It is known that in breast cancer biology, autophagy mainly plays a cytoprotective and anti-apoptotic role in vitro, being conceivably responsible for cell resistance to drug exposure and a higher metastatic attitude in vivo. Thus, the development of novel autophagy-targeting agents represents a valuable strategy to improve the efficacy of anticancer interventions. It is widely acknowledged that the enormous biodiversity of marine organisms represents a highly promising reserve for the isolation of bioactive primary and secondary metabolites targeting one or several specific molecular pathways and displaying active pharmacological properties against a variety of diseases. The aim of this re…
Novel molluskan biomineralization proteins retrieved from proteomics: a case study with upsalin.
2012
12 pages; International audience; The formation of the molluskan shell is regulated by an array of extracellular proteins secreted by the calcifying epithelial cells of the mantle. These proteins remain occluded within the recently formed biominerals. To date, many shell proteins have been retrieved, but only a few of them, such as nacreins, have clearly identified functions. In this particular case, by combining molecular biology and biochemical approaches, we performed the molecular characterization of a novel protein that we named Upsalin, associated with the nacreous shell of the freshwater mussel Unio pictorum. The full sequence of the upsalin transcript was obtained by RT-PCR and 5'/3…
Determining seasonality of mussel collection from an early historic Inuit site, Labrador, Canada: Comparing thin-sections with high-resolution stable…
2018
International audience; Stable oxygen isotope (delta O-18) analysis of mussels (Mytilus sp.) from a 16th to mid-18th century Inuit site in southern Labrador, Canada, indicates multiple seasons of shellfish collection, and by proxy, multiple seasons of site occupation. High-resolution delta O-18 sampling of shell permits a precise season of mussel collection since the temperature and freshwater signal of the local water is retained in the shell. Live-collected specimens of Mytilus sp. obtained from Labrador, were analyzed for stable oxygen isotopes and for growth patterns. These data were used to interpret results from the archaeological shells. Growth pattern analysis was conducted to test …
Differential effects of calcium channel antagonists (omega-conotoxin GVIA, nifedipine, verapamil) on the electrically-evoked release of [3H]acetylcho…
1990
Electrically-evoked release of [3H]acetylcholine from autonomic neurons (myenteric plexus), motoneurons (phrenic nerve) and the central nervous system (neocortex) was investigated in the presence and absence of the calcium channel antagonists omega-conotoxin GVIA, nifedipine and verapamil, whereby the same species (rat) was used in all experiments. Release of [3H]acetylcholine was measured after incubation of the tissue with [3H]choline. omega-Conotoxin GVIA markedly reduced (70%) the evoked release of [3H]acetylcholine from the myenteric plexus of the small intestine (IC50: 0.7 nmol/l) with a similar potency at 3 and 10 Hz stimulation. An increase in the extracellular calcium concentration…
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 …