| dc.description.abstract | Zebrafish is a vertebrate model largely used in ecotoxicology to unveil and predict the effects of hazardous substances that are present in the aquatic environment. However, more research is needed on developmental adverse effects due to exposures to polycyclic aromatic hydrocarbons (PAHs). Previous studies focused on high molecular weight (HMW) PAHs due to their higher toxicity. Nevertheless, low molecular weight (LMW) PAHs are the main constituent of the water-soluble fraction of diesel oil and have been shown to have high cardiotoxicity in developing fish. Therefore, we studied biological parameters commonly associated with effects due to three-ring PAH exposure. In this study zebrafish embryos were exposed to three different mixtures, Mixture 1 containing parental three-ringed PAHS, Mixture 2 with two methylated phenanthrenes, and Mixture 3 was like Mixture 1 with the addition of naphthalene. The selected parameters were uninflated swim bladder, pericardial edema and yolk sac edema. In addition, survival and hatching were also observed. A PCR screening of the embryos was carried out using various target genes, cyp1a, mt2, nrf2a, tsh, vtg1, vtg2 and nfκβ. Although the exposure did not show significant difference between control and treated groups, there were indications of increasing lesions with increased concentration of PAHs for each mixture treatment. However, the experiments should be repeated and extended to confirm these findings. | |