Ecotoxicological effects of crude oil on Danio rerio early life stages: a molecular, morphological and behavioral approach focused on swim bladder development.

Proper development and inflation of the swim bladder is essential for swimming and foraging behavior in fish. To characterize the effects of the Brazilian oil spill that occurred between 2019 and 2020 to early life stage fish, the expression of genes involved in swim bladder development were targeted, with biochemical assays, morphology, and behavior assessed. The swim bladder was focused on due to recent findings of being a target of polycyclic aromatic hydrocarbons (PAHs) present in oil.

Cigarette butt leachates induce alterations in gene expression and damage in health status of tropical oysters.

Cigarette butts (CB) are among the most frequent debris in marine litter collected in coastal areas. They are potential sources of chemical contamination by leaching process, posing risks to biota. This study aimed to evaluate the short-term impacts of CB leachates on the oyster Crassostrea brasiliana.

First evidence of transcriptional modulation by chlorothalonil in mussels Perna perna.

Gills are considered a key player in organism defenses against environmental pollutants. Since it is the major site of uptake of waterborne chemicals, the modulation of important cellular defenses is expected in this tissue. Chlorothalonil, a fungicide presented in herbicides and antifouling paints, might be responsible for toxicity in marine biota.

Stress responses in Crassostrea gasar exposed to combined effects of acute pH changes and phenanthrene.

Ocean acidification is a result of the decrease in the pH of marine water, caused mainly by the increase in CO released in the atmosphere and its consequent dissolution in seawater. These changes can be dramatic for marine organisms especially for oysters Crassostrea gasar if other stressors such as xenobiotics are present. The effect of pH changes (6.

Induced gene expression in oyster Crassostrea gigas exposed to sewage.

Pacific oysters, Crassostrea gigas, were exposed to untreated sewage diluted in seawater. After 48h of exposure, the expression of genes associated to biotransformation pathways (CYP356A1, GSTO, MDR, FABP and ALAS) were analyzed in gills through semi-quantitative RT-PCR. A significant induction in all genes analyzed in the sewage-exposed oysters was observed.

Comparison of the antioxidant defense system in Crassostrea rhizophorae and Crassostrea gigas exposed to domestic sewage discharges.

Oysters Crassostrea rhizophorae and Crassostrea gigas were kept for fourteen days at four sites in São José, SC, Brazil, chosen according to a sewage discharge contamination gradient. Enzymatic activities of CAT, GST, G6PDH and GR were evaluated in gills and digestive glands. Higher CAT activity was observed in tissues of C.

Differential gene expression in oyster exposed to sewage.

In order to investigate the influence of domestic sewage on the gene expression of Pacific oysters Crassostrea gigas, suppression subtractive hybridization (SSH) method was employed. Oysters were sampled at a farming area and, after 10 days of acclimation in the laboratory, were exposed to untreated domestic sewage diluted 33% for 48 h. Gills of male oysters were excised for total RNA extraction.

Cloning a new cytochrome P450 isoform (CYP356A1) from oyster Crassostrea gigas.

We have cloned the full-length cDNA of the first member of a new cytochrome P450 (CYP) family from the Pacific oyster Crassostrea gigas. This new CYP gene was obtained based on an initial 331bp fragment previously identified among the list of the differentially expressed genes in oysters exposed to untreated domestic sewage. The full-length CYP has an open reading frame of 1500bp and based on its deduced amino acid sequence was classified as a member of a new subfamily, CYP356A1.

Antioxidant enzymes and thiol/disulfide status in the digestive gland of the brown mussel Perna perna exposed to lead and paraquat.

Lead (Pb) and paraquat (PQ) have different toxic mechanisms associated with cell damage. Pb may induce alterations in zinc containing proteins, including the known inhibitory effect on the enzyme delta-aminolevulinic acid dehydratase, disrupting the heme-synthesis pathway. During PQ biotransformation, redox cycle reactions enhance oxyradical production, which may lead to pro-oxidative conditions.