Study of the marine pollution by hydrocarbons and characterization of their biochemical and molecular effects on clam Ruditapes sp.

• Main Author: Chalghmi, Houssem
• Other Authors: Environnements et Paléoenvironnements OCéaniques (EPOC), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Université de Bordeaux, Université de Monastir (Tunisie), Jean-Paul Bourdineaud, Dalila Saidane-Mosbahi
• Format: Doctoral or Postdoctoral Thesis
• Language: French
• Published: HAL CCSD 2015
• Subjects: Tunis lagoon; Bivalves; PAHs; Metals; Benzo(a)pyrene; Biochemical biomarkers; Histology; Transcriptomic response; Genotoxicity; Lagune de Tunis; HAPs; Métaux; Benzo(a)pyrène; Marqueurs biochimiques; Histologie; Réponse transcriptomique; Génotoxicité; [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry; [SDV.TOX.ECO]Life Sciences [q-bio]/Toxicology/Ecotoxicology; Crassostrea gigas
• Online Access: https://theses.hal.science/tel-01583022; https://theses.hal.science/tel-01583022/document; https://theses.hal.science/tel-01583022/file/CHALGHMI_HOUSSEM_2015.pdf

Firstly, biomonitoring of Tunis lagoon was conducted during one year using an approach combining chemicals and biological analyses and the bioindicator species Ruditapesdecussatus. This approach high lighted the high contamination of the Tunis lagoon by tracemetals and polycyclic aromatic hydrocarbons (PAHs). Seasonal variation of contaminant bioaccumulation levels in clam was found to be strongly associated with physico chemical changes in surrounding environment and physiological processes in organism. Biological responses investigated through a battery of exposure and effect biomarkers located at differentlevels of biological organisation: molecular (expression of five genes), biochemical(benzo(a)pyrene hydroxylase, glutathione S-transferase, acetylcholinesterase and catalase activities and malondialdehyde concentration) and tissular (histopathological damages),demonstrated a defense process modulation by pollution and showed histopathological alterations in gills and digestive gland involving severe impact of contaminants on health stateof clam. The study of spatio temporal interactions between abiotic and biotic factors identified temperature and reproduction as main parameters affecting defense and effect biochemical response. The principal component analysis (PCA), using all analyzed parameters during thespring, allowed to identify site Z2 as the most affected by pollution. Secondly,benzo(a)pyrene (BaP), already identified in Tunis lagoon, was used in controlled conditions at the laboratory in order to characterize the molecular and biochemical responses in bivalves(Ruditapes philippinarum and Crassostrea gigas) facing a subacute and acute exposures tothis contaminant. This study showed a modulation of biochemical biomarkers of metabolism,oxidative stress and neurotoxicity and expression of genes involved in process of metabolisation, mitochondrial respiration, antioxidant defense, reproduction and immune defense. The analysis of DNA damages revealed a high and early genotoxicity effect of BaPin both ...