The use of physicochemical properties to assess changes in the cuticle structure of crustaceans: Case of the prawn Palaemon serratus and its moult cycle.

The crustacean cuticle is a composite material acting as a shell, but also linked with other physiological functions as respiration, locomotion or reproduction. The present study aimed to characterize for the first time the cuticle properties of the marine prawn Palaemon serratus using thermal (TGA) and chemical (FTIR, ICP-AES) techniques. The use of native lyophilized cutiles also enabled to estimate the complexity of the cuticle structure of P.

Larval feeding activity and use of embryonic resources determine juvenile performance of the common prawn Palaemonserratus.

Phenotypic links are the potential for "carryover" of effects of experience during one life history stage into performance and selection at subsequent stages. They reflect plastic responses to the environment experienced during an early phase on the phenotype of subsequent phases. We are studying these effects by following individuals of the shrimp Palaemon serratus from the embryonic (eggs carried by females) through the larval phase (pelagic) to the juvenile phase (benthic).

Cadmium Highlights Common and Specific Responses of Two Freshwater Sentinel Species, and .

Zebra mussel (ZM), , commonly used as a sentinel species in freshwater biomonitoring, is now in competition for habitat with quagga mussel (QM), This raises the question of the quagga mussel's use in environmental survey. To better characterise QM response to stress compared with ZM, both species were exposed to cadmium (100 µg·L), a classic pollutant, for 7 days under controlled conditions. The gill proteomes were analysed using two-dimensional electrophoresis coupled with mass spectrometry.

Advancing environmental monitoring across the water continuum combining biomarker analysis in multiple sentinel species: A case study in the Seine-Normandie Basin (France).

Nowadays, biomarkers are recognized as valuable tools to complement chemical and ecological assessments in biomonitoring programs. They provide insights into the effects of contaminant exposures on individuals and establish connections between environmental pressure and biological response at higher levels. In the last decade, strong improvements in the design of experimental protocols and the result interpretation facilitated the use of biomarker across wide geographical areas, including aquatic continua.

Combined effects of temperature and diet on the performance of larvae produced by young and old Palaemon serratus females.

Seasonal variations in environmental conditions determine the success of decapod larval development, and females transmit more energy in sub-optimal conditions to maximise the fitness of their offspring. The objective of this study was to focus on the combined effects of temperature (14, 18 and 22 °C) and food quality on the performance of larvae produced by 5 young (0+) and 5 old (I+) Palaemon serratus females. We prepared 3 diets based on Artemia, in decreasing order of total fatty acid content: freshly hatched nauplii (N), unenriched metanauplii (M) and metanauplii enriched with a mixture of microalgae (ME).

N-acetyl-β-D-glucosaminidase measurement on the freshwater amphipod Gammarus fossarum: development, biological variability and application in an ecotoxicological approach.

Due to its role in the crustacean moulting process, N-acetyl-β-D-glucosaminidase (NAGase) is interesting to monitor the good proceeding of the moult cycle, as well as relevant in assessing changes in the moulting process caused by stressors. The present study aimed to measure the NAGase activity to monitor the moulting process of the freshwater amphipod Gammarus fossarum. Firstly, an optimised protocol measuring the NAGase activity was made, allowing a robustness and reproducibility of measurements.

Modulation of haemocyte motility by chemical and biological stresses in Mytilus edulis and Dreissena polymorpha.

Mussels are constantly exposed to various pollutants in the environment, which can impair their immune defences against microbes and thus threaten their survival. In this study, we expand the insight into a key parameter of immune response in two mussel species by exploring the impact of exposure to pollutants or bacteria or simultaneous chemical and biological exposure on haemocyte motility. Basal haemocyte velocity in primary culture was high and increasing over time in Mytilus edulis (mean cell speed of 2.

Comparative immune responses of blue mussel and zebra mussel haemocytes to simultaneous chemical and bacterial exposure.

Biomonitoring at the scale of the aquatic continuum and based on biomarkers, requires various representative species and a knowledge of their sensitivity to contaminants. Mussel immunomarkers are established tools for evaluating immunotoxic stress, but little is known about the consequences of an immune activation by local microorganisms on their response to pollution. This study aims to compare the sensitivity of cellular immunomarkers in two mussel species from different environments, the marine mussel Mytilus edulis (blue mussel) and the freshwater mussel Dreissena polymorpha (zebra mussel), to chemical stressors combined with bacterial challenge.

Effects of Chemical Compounds on the Activity of the N-acetyl-β-D-Glucosaminidase of the Marine Prawn, Palaemon serratus: Screening In Vitro.

N-acetyl-β-D-glucosaminidase (NAGase) is important for crustaceans because the enzyme activity is necessary for the molting process. The present study aimed to assess the sensitivity of Palaemon serratus NAGase activity to a set of compounds of diverse chemical families in the context of in vitro exposures. Compounds representing different chemical families were selected according to their abundance, impact in the environment, and relevance as disruptors of the molting process.

Temperature-mediated developmental plasticity in winter and summer larvae of Palaemon serratus.

In a seasonal environment, variation in larval phenotype and developmental plasticity allow crustacean larvae to maximise survival by lengthening or shortening their development. The aim of this study is to investigate the effects of temperature, laying season and their interaction on larval developmental pathways (larval instars and larval stages). We monitored the different larval stages and calculated the number of larval instars reached during the development of winter and summer larvae of Palaemon serratus incubated at 12, 16 or 20 °C.

Centrosome, the Newly Identified Passenger through Tunneling Nanotubes, Increases Binucleation and Proliferation Marker in Receiving Cells.

Type 1 tunneling nanotubes (TNTs-1) are long, cytoplasmic protrusions containing actin, microtubules and intermediate filaments that provide a bi-directional road for the transport of various components between distant cells. TNT-1 formation is accompanied by dramatic cytoskeletal reorganization offering mechanical support for intercellular communication. Although the centrosome is the major microtubule nucleating center and also a signaling hub, the relationship between the centrosome and TNTs-1 is still unexplored.

Blue mussel (Mytilus edulis)-A bioindicator of marine water contamination by protozoa: Laboratory and in situ approaches.

Aims: The protozoan parasites Cryptosporidium spp., Giardia duodenalis and Toxoplasma gondii are identified as public health priorities and are present in a wide variety of environments including the marine ecosystem. The objective of this study was to demonstrate that the marine bivalve blue mussel (Mytilus edulis) can be used as a tool to monitor the contamination of marine waters by the three protozoa over time.

N-acetyl-β-d-glucosaminidase activity in Palaemon serratus - Methodological optimisation and intrinsic variability.

Chitinolytic enzymes fulfil a key role in the moulting process of crustaceans, in degrading the endocuticle during apolysis. Measuring the enzyme activity is an interesting manner to monitor the moult process at sub-individual level, complementary to the classical observation of the integument morphogenesis, ecdysis success, or moult cycle duration. The present study aimed to optimise the methodology of using N-acetyl-β-D-glucosaminidase (NAGase) activity to monitor moulting in the marine prawn Palaemon serratus, and to compare NAGase activity levels along the moult cycle of both male and female specimens.

Comparison of viability and phagocytic responses of hemocytes withdrawn from the bivalves Mytilus edulis and Dreissena polymorpha, and exposed to human parasitic protozoa.

Bivalve molluscs are now considered indicator species of aquatic contamination by human parasitic protozoa. Nonetheless, the possible effects of these protozoa on the immune system of their paratenic hosts are poorly documented. The aim of this study was to evaluate the effects of two protozoa on hemocyte viability and phagocytosis from two mussels, the zebra mussel (freshwater habitat) and the blue mussel (seawater habitat).

Direct and indirect P-glycoprotein transfers in MCF7 breast cancer cells.

The efflux protein P-glycoprotein (P-gp) is over expressed in many cancer cells and has a known capacity to confer multi-drug resistance to cytotoxic therapies. We provide a mathematical model for the direct cell-to-cell transfer of proteins between cells and the indirect transfer between cells and the surrounding liquid. After a mathematical analysis of the model, we construct an adapted numerical scheme and give some numerical simulations.

Highly polluted life history and acute heat stress, a hazardous mix for blue mussels.

Intertidal sessile organisms constitute through their life history unintended stress recorders. This study focuses on the impact of pollution on Mytilus edulis ability to cope with an additional stress. For this purpose, two acclimation stages to different temperatures were conducted before an acute stress exposure in mussels collected from a heavily polluted site.

Use of sperm DNA integrity as a marker for exposure to contamination in Palaemon serratus (Pennant 1777): Intrinsic variability, baseline level and in situ deployment.

In a previous study, the Comet assay was optimized for Palaemon serratus prawns in order to propose a biomarker for sperm quality in this species. However, better knowledge of its basal level and its natural variability, related to intrinsic biotic and environmental abiotic factors, is required before any relevant use of this biomarker in the field. To fulfill this goal, the present study proceeded in three steps: (i) the temporal variability of DNA integrity was followed monthly in a reference population over a 2-year period, (ii) the correlation between the main intrinsic biotic (i.

Multixenobiotic resistance in Mytilus edulis: Molecular and functional characterization of an ABCG2- type transporter in hemocytes and gills.

Among the cellular protection arsenal, ABC transporters play an important role in xenobiotic efflux in marine organisms. Two pumps belonging to B and C subfamily has been identified in Mytilus edulis. In this study, we investigated the presence of the third major subtype ABCG2/BCRP protein in mussel tissues.

Infection dynamics of a V. splendidus strain pathogenic to Mytilus edulis: In vivo and in vitro interactions with hemocytes.

The pathogenic strain V. splendidus 10/068 1T1 has previously been reported for its virulence to the blue mussel and for its capacity to alter immune responses. In this study, we expanded the knowledge on hemocyte-pathogen interactions by using in vitro and in vivo assays.

Neuroendocrine disruption in the shore crab Carcinus maenas: Effects of serotonin and fluoxetine on chh- and mih-gene expression, glycaemia and ecdysteroid levels.

Serotonin, a highly conserved neurotransmitter, controls many biological functions in vertebrates, but also in invertebrates. Selective serotonin reuptake inhibitors (SSRIs), such as fluoxetine, are commonly used in human medication to ease depression by affecting serotonin levels. Their residues and metabolites can be detected in the aquatic environment and its biota.

Consequences of acclimation on the resistance to acute thermal stress: Proteomic focus on mussels from pristine site.

Climate change constitutes an additional threat for intertidal species that already have to cope with a challenging environment. The present study focuses on the blue mussel Mytilus edulis and aims at investigating the importance of thermal acclimation in heat stress response. Microcosm exposures were performed with mussels submitted to an identical acute thermal stress following two thermal summer acclimations standing for present or future temperature conditions.

Evidence for P-Glycoprotein Involvement in Cell Volume Regulation Using Coulter Sizing in Flow Cytometry.

The regulation of cell volume is an essential function that is coupled to a variety of physiological processes such as receptor recycling, excitability and contraction, cell proliferation, migration, and programmed cell death. Under stress, cells undergo emergency swelling and respond to such a phenomenon with a regulatory volume decrease (RVD) where they release cellular ions, and other osmolytes as well as a concomitant loss of water. The link between P-glycoprotein, a transmembrane transporter, and cell volume regulation is controversial, and changes in cells volume are measured using microscopy or electrophysiology.

Structural and functional analysis of tunneling nanotubes (TnTs) using gCW STED and gconfocal approaches.

Background Information: Tunneling nanotubes (TnTs) are thin plasma membrane bridges mediating transfers of materials and signals between cells. Heterogeneity of heterocellular and homocellular TnTs is largely described but ultrafine imaging of these light-sensitive floating nanometric structures represents a real challenge in microscopy. We propose here imaging strategies designed to dissect structural and dynamic aspects of TnT formation and function in fixed or living PC12 cells.