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CONTENT - International Society of Zoological Sciences

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S19 ICZ2008 - Abstracts<br />

In vitro methods for the detection <strong>of</strong> algal neurotoxins to<br />

secure shellfish and fish consumption<br />

Aurélie Ledreux 1,2 , Sophie Krys 2 and Cécile Bernard 1<br />

1 Muséum National d’Histoire Naturelle, USM 505/EA 4105<br />

Ecosystèmes et interactions toxiques, 57 rue Cuvier, CP 39,<br />

75231 Paris cedex 05, France<br />

2 Agence Française de Sécurité Sanitaire des Aliments, Unité<br />

Toxines, Polluants Organiques et Pesticides, 23 avenue du<br />

Général de Gaulle, 94706 Maisons-Alfort cedex, France<br />

The global occurrence <strong>of</strong> toxic algal blooms has increased in<br />

frequency and intensity over the past 20 years, resulting in an<br />

increase in the number <strong>of</strong> shellfish production area affected by<br />

phycotoxins (Hallegraeff, 2003).<br />

To keep shellfish and fish consumption secure, the risk<br />

management associated to phycotoxin contamination in shellfish<br />

and fish is based on monitoring <strong>of</strong> toxins in seafood destined to<br />

human consumption (Yasumoto, 1995). The available chemical<br />

methods, while being efficient for the detection <strong>of</strong> identified toxins<br />

are inadequate for the detection <strong>of</strong> emerging toxins or unknown<br />

analogues. As a consequence, detection <strong>of</strong> algal toxins is still<br />

based on mouse bioassays in spite <strong>of</strong> their poor sensibility, their<br />

lack <strong>of</strong> specificity and the ethical issue.<br />

Alternative assays are required which are reliable, sensitive and<br />

able to detect toxic agents depending on the molecular mechanism<br />

by which they affect biological systems. In vitro methods are<br />

attractive since they are inexpensive and allow a rapid screening<br />

<strong>of</strong> a large number <strong>of</strong> samples.<br />

The aim <strong>of</strong> this study was to determine if the specific detection <strong>of</strong><br />

three neurotoxins families (saxitoxins, brevetoxins and palytoxin<br />

and analogues), acting on two different cellular targets can be<br />

performed by using a single neuroblastoma cell-line (Neuro-2a).<br />

To that end, pure toxins have been tested in order to evaluate the<br />

sensibility <strong>of</strong> the Neuro-2a cell based assay. The specificity <strong>of</strong> the<br />

assay for each type <strong>of</strong> toxins was achieved by the use <strong>of</strong> two<br />

antagonists: ouabain and veratridine. The matrix effect was<br />

assessed by testing algal extracts and mussel extracts.<br />

Bioaccumulation <strong>of</strong> heavy metals in the tissues <strong>of</strong> two<br />

flatfishes (Platichtys flesus and Solea vulgaris) from the outer<br />

coast and Ría <strong>of</strong> Vigo, NE Atlantic (Spain)<br />

Lazhar M’Hadhbi 1,2 , Dragos Zaharescu 2 , Tahar Gharred 3 , Antonio<br />

Palanca 2 and Moncef Boumaïza 1<br />

1 Hydrobiology Unit, Enironmental Biomonitoring Laboratory,<br />

Faculty <strong>of</strong> <strong>Sciences</strong>, Bizerte, Zarzouna 7021, Tunisia<br />

2 Animal Anatomy Laboratory, Vigo University, 36310 Vigo,<br />

Spain<br />

3 Marine Biotechnological Institute <strong>of</strong> Monastir,Tunisia<br />

Concentrations <strong>of</strong> ten heavy metals (Cd, Pb, Hg, Cu, Zn, As, Se,<br />

Ag, Mn, Sn) in liver, muscle and kidney <strong>of</strong> European flounder<br />

(Platichtys flesus) and the sole (Solea vulgaris) from Ria <strong>of</strong> Vigo<br />

and its coastal zone (Spain) were measured from April 2006 to<br />

February 2007 and the relationships between fish size (length and<br />

weight), age, gender, season and metal concentrations in the<br />

tissues was investigated.<br />

The average metal concentrations in different organs varied in the<br />

following ranges: Cd (0.01- 2.08), Pb (0.02- 2.91), Hg (0.015- 2.13),<br />

Cu (2.5- 46.71), Zn (12.7- 996.7), As (1.2- 151.9), Se (1.56- 34.02),<br />

Ag (0.01- 5.81), Mn (0.27- 57.26), Sn (0.01 to 5.07) µg g -1 dry<br />

weight. Fish kidney and liver registered highes levels <strong>of</strong> Cd, Cu, Pb<br />

and Zn, whereas the muscles registred highest Hg concentrations.<br />

Platichtys flesus tended to accumulate more quantities than Solea<br />

vulgaris. A comparison <strong>of</strong> metals concentration in fishes from both<br />

sites shown higher bioaccumulation in those exemplars from the<br />

Ria <strong>of</strong> Vigo. This means a tendency <strong>of</strong> higher pollution levels in the<br />

estuarine environment. Seasonal variability generally indicated<br />

increased levels <strong>of</strong> metals bioaccumulation during winter, the<br />

period <strong>of</strong> heavy rains and high flows from the surrounding Vigo<br />

cityscape.<br />

Although, generally, metals levels in the tissues <strong>of</strong> fish in the area<br />

are not harmful for humans, measures shall be taken to lower<br />

heavy metals inputs into Ria <strong>of</strong> Vigo.<br />

- 74 -<br />

Global quantitative analysis <strong>of</strong> protein phosphorylation status<br />

in liver <strong>of</strong> fish exposed to the Cyanotoxin Microcystin<br />

Mélodie Malécot 1 , Karim Mezhoud 1 , Danièle Praseuth 2,3 , Arul<br />

Marie 4 , Simone Puiseux-Dao 1 and Marc Edery 1<br />

1 USM 505/EA 4105 Écosystèmes et interactions toxiques,<br />

Département de « Régulations, développement et diversité<br />

moléculaire », Muséum national d’Histoire naturelle, 12 rue Buffon,<br />

F-75231 Paris Cedex 05, France ; 2 INSERM, U 565 and 3 MNHN,<br />

USM 503 Laboratoire des Régulations et dynamique des génomes,<br />

Département de « Régulations, développement et diversité<br />

moléculaire », CNRS, UMR 5153, Acides nucléiques: dynamique,<br />

ciblage et fonctions biologiques, Muséum national d’Histoire<br />

naturelle, 57 rue Cuvier, CP26, F-75231 Paris Cedex 05, France ;<br />

4 Plateforme de spectrométrie de masse et de protéomique,<br />

Département de « Régulations, développement et diversité<br />

moléculaire », Muséum National d’Histoire Naturelle, 63 rue Buffon,<br />

F-75231 Paris Cedex 05, France<br />

Microcystins (MCs) are hepatotoxins inhibiting protein<br />

phosphatases PP1 and PP2A. These peptides produced by some<br />

freshwater cyanobacteria are getting attention due to their acute<br />

toxicity and tumor-promoting activity. To date, the detailed<br />

mechanisms underlying their toxicity are unknown. MC-leucinearginine<br />

(MC-LR) is the most toxic and the most commonly<br />

encountered MC variant in aquatic environment. Toxicological<br />

investigations on the liver <strong>of</strong> the aquatic model, the medaka fish,<br />

have been performed with differential proteome analyses <strong>of</strong> MC-<br />

LR-treated (by 2 exposure routes; water or food contamination)<br />

and untreated medaka fish in order to investigate the<br />

mechanisms <strong>of</strong> establishment <strong>of</strong> early responses to the toxin.<br />

Cytosolic, membrane and organelle proteins from livers were<br />

resolved by 2D electrophoresis and detected using stains specific<br />

for phosphoproteins and for whole protein content. Overall, more<br />

than 100 spots were found to vary significantly on the proteomic<br />

2D maps or on the phosphoproteomic 2D maps. Of these, 32<br />

proteins could be identified by mass spectrometry. Among them,<br />

phenylalanine hydroxylase, keratin 18 (type I) and grp78 showed<br />

variations in phoshoryl content that could be directly associated<br />

with inhibition <strong>of</strong> PP activity. The other identified proteins<br />

exhibited variations in their expression level. The identified<br />

proteins appear to be involved in cytoskeleton assembly, cell<br />

signalling, oxidative stress and apoptosis. The reported<br />

methodology should be widely used to a number <strong>of</strong> tissues and<br />

organisms, thus helping in the search for biomarkers <strong>of</strong> MC-LR<br />

contamination.<br />

Study <strong>of</strong> the insecticidal activity <strong>of</strong> alkaloids <strong>of</strong> the<br />

hairybroom (Cytisus triflorus L’Hér.) and <strong>of</strong> the bacterium<br />

Bacillus thuringiensis against the desert locust Schistocerca<br />

gregaria<br />

Hakima Mohand Kaci 1 , Karima Ait-Kaci 1 , Bahia Doumandji-<br />

Mitiche 2 and Fethia Fazouane 1<br />

1 Faculty <strong>of</strong> <strong>Sciences</strong>, Department <strong>of</strong> Biology, University <strong>of</strong><br />

Boumerdes, Algeria; 2 El Harrach National Agronomy Institute,<br />

Alger, Algeria<br />

In many regions <strong>of</strong> Africa and Asia (including Algeria), in addition<br />

to abiotic factors such as climate, food security relies mainly on<br />

crop protection. Crops are under attack from locusts, e.g. the<br />

desert locust S. gregaria. Among existing forms <strong>of</strong> control, are<br />

those involving entomopathogenous microorganisms, e.g. the<br />

bacterium B. thuringiensis, or acridicide natural products, e.g.<br />

those extracted from the shrub C. triflorus. In the present work, we<br />

compare the effects <strong>of</strong> B. thuringiensis and alkaloids <strong>of</strong> C. triflorus<br />

on digestive tract histology <strong>of</strong> the <strong>of</strong> adult locusts and on three<br />

physiological parameters: heart rate, respiratory rate and<br />

haemocyte number. The digestive tract anatomy <strong>of</strong> control and<br />

treated animals appeared identical. Histological examination <strong>of</strong> the<br />

three parts <strong>of</strong> the digestive tract (stomodeum, mesenteron and<br />

proctodeum) <strong>of</strong> locusts treated with alkaloids and by the bacterium<br />

showed that histological changes occurred in the three parts.

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