Vitelogenin from the prawn Macrobrachium borellii as hydrocarbon pollution biomarker.

F GARCIA; M CUNNINGHAM; R POLLERO; H HERAS

Los cocos. Cordoba. Argentina

Congreso; Sociedad de Toxicología y Química Ambiental. Simposio SETAC Argentina.; 2006

Sociedad de Toxicología y Química Ambiental. Simposio SETAC

During reproduction, the female-associated lipoprotein Vitellogenin (VTG) is transported from the hemolymph into the vitellogenic oocytes as a precursor for the synthesis of the egg yolk vitellin (VT). VTG synthesis is affected by environmental stressors, and therefore is a widely used biomarker in studies of endocrine disruption induced by xenobiotics. However, little work has been done using it to evaluate hydrocarbon pollution. Using purified VT from the autochthonous freshwater prawn Macrobrachium borellii, a representative of La Plata River Estuary, we have developed an anti-vitellogenin ELISA for the assessment of the possible impact on reproduction of a short exposure to the water-soluble fraction of crude oil (WSF). The specificity of the antibodies was checked by Western Blot analysis of hemolymph and ovary extracts. No cross-reacting proteins were observed and VTG was strongly recognized by the anti-VT polyclonal antibody. Females at different vitellogenic stages were exposed to a sub lethal concentration of WSF (mostly a mixture of low-boiling aromatics which closely resembles the aromatic hydrocarbon of diesel oil fuel). After a 7-day exposure, samples of hemolymph and gonad were taken. Typical VTG values for control prawn were within the range reported for other crustaceans. VT values were positively correlated with the gonadosomatic index (indicative of the vitellogenic stage). All exposed animals increased their VTG and VT titer, regardless of the vitellogenic stage, indicating significant changes in oogenesis and showed increases in exposed females that ranged from 20% (VT) to 70 % (VTG) as compared to the control organisms. These results indicate that VTG levels in M. borellii are upregulated and highly sensitive to WSF exposure. Prawn was exposed at hydrocarbon levels that are found in the aquatic environment after an oil spill or diesel discharge, so this assay could potentially be employed as a biomarker for hydrocarbon pollution in La Plata River environment.