CONICET | Buscador de Institutos y Recursos Humanos

During reproduction, the female-associated lipoprotein vitellogenin (VTG) is transported from hemolymph to the vitellogenic oocytes as a precursor for the synthesis of the egg yolk vitellin (LV). VTG synthesis is affected by environmental stressors, therefore it is widely used as biomarker in studies on endocrine disruption induced by xenobiotics. However, little work has been done concerning its use so as to evaluate hydrocarbon pollution. Purified LV from the autochthonous freshwater shrimp Macrobrachum borellii, representative of Río de la Plata river, was utilized to develop an anti-vitellin ELISA for the assessment of the posible impact on reproduction after a short exposure to the water-soluble fraction of crude oil (WSF). No cross-reacting proteins were detected, but VTG was strongly recognized by the anti-LV 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 resemblesthe 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 found to be within the range already reported for other crustaceans. LV values were positively correlated with the gonadosomatic index (GSI). All the exposed animals with GSI higher than 7 increased their VTG and LV titer (190% and 140% as comparated to the control organisms) regardless of the vitellogenic stage, indicating significant changes in oogenesis.These results indicated that VTG levels in M. borellii are upregulated and highly sensitive to WSF exposure. Prawns were exposed to hydrocarbon levels that were 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 the freshwater environment.