Gene expression profiles of putative biomarkers in juvenile loggerhead sea turtles (Caretta caretta) exposed to polycyclic aromatic hydrocarbons.

Abstract There is evidence that polycyclic aromatic hydrocarbons (PAHs) are consistently the predominant organic contaminants in concentration found in loggerhead sea turtles (Caretta caretta) from the North and Central Adriatic Sea. Hence this study investigates the PAH toxicity to loggerheads by using a particular set of genes [ i.e. CYP1B, CAT, GPX, GSTT1, SOD3, DNMT1, Epoxide hydrolase 1 (EPHX1), Poly (ADP-ribose) polymerase 1 (PARP1), Lamin-A/C isoform 3 (LMNA), Talin 1 (TLN1), Annexin A1 (ANXA1)] whose altered expression is potentially dependent on and specific for the PAH-related mechanism of action. Twenty healthy juvenile loggerheads were thus divided into high and low exposure groups (mean of ΣPAHs: 80.34 ng mL⁻¹ vs. 8.84 ng mL⁻¹, P < 0.0001) according to the median split of ΣPAHs. Interestingly, we found that the whole blood mRNA levels of each gene biomarker tested were significantly increased in high PAH-exposed turtles thus proving to be useful for the biological monitoring of PAH toxicity and hematotoxicity in sea turtles. Graphical abstract Image 1 Highlights • We examined potential PAH-related biomarkers in whole blood of loggerheads captured alive. • The PAH levels can be associated with selected gene biomarkers transcript levels. • CYP1B, NADP, LMNA and DNMT1 showed the highest gene expression levels. • Whole blood TBARS have been shown to be elevated in high PAH-exposed turtles. • We suggest links between PAH exposure and potential adverse outcomes in sea turtles. This study provides new insights into the relationship between changes in mRNA abundance profiles of specific gene biomarkers and plasma levels of total PAHs in C. caretta turtles. Our results further support the potential of using whole blood cell gene biomarkers for monitoring the impact of environmental contaminants on sea turtles. [ABSTRACT FROM AUTHOR]