Vitellogenin (VTG) conservation in sea turtles: anti-VTG antibody in Chelonia mydas versus Caretta caretta.

Vitellogenin (VTG) is considered as a marker of endocrine disruption. A Western blot method for VTG quantification in Caretta caretta turtle plasma was developed using anti-VTG antibody for Chelonia mydas. A screening of samples (n = 61) collected in the southern Mediterranean Sea around Lampedusa Island, Italy, was performed. The antibody showed a good cross-reactivity with C. caretta VTG, suggesting a certain conservation of the core of the protein in different sea turtle species. The optimal operative condition for Western blot analysis consists of using diluted plasma at 1:50. In field samples, a certain mismatch with morphological sexing was observed, and VTG was detected in young animals. These results suggest the possibility of a precocious activation of VTG-encoding genes before sexual maturation and/or exposure to endocrine disrupter substances.