Regenerative response and endocrine disrupters in crinoid echinoderms: Armregeneration in Antedon mediterranea after experimental exposure to polychlorinated biphenyls

Regenerative phenomena, which have the advantage of reproducing development al processes in the adult organism, are very sensitive to environmental str ess and represent stages that can be monitored for damage at the whole-orga nism, cellular and molecular levels. Some persistent and ubiquitous polluta nts, which can affect the natural environment because of their bioaccumulat ion in organisms, exert their effects by acting as 'endocrine disrupters'. In this respect, they can cause dysfunction in steroid hormone production/m etabolism and activity by their dramatic effects on gene expression, reprod uctive competence and growth. The aim of our present research was to assess the impact of such compounds on adult echinoderm reproductive physiology w ith particular reference to regeneration potential. It is known that verteb rate-type steroids are synthesized by echinoderms and play a role in the co ntrol of growth and reproduction. Our experimental model is the crinoid Ant edon mediterranea, selected on the basis of its previously explored regener ative capabilities at the level of the arms. The regeneration response, ana lyzed at the tissue and cellular levels using both light and electron micro scopy and immunocytochemistry, was employed to monitor the effects of expos ure to persistent endocrine disrupter micropollutants such as polychlorinat ed biphenyls (PCBs) by means of laboratory tests performed under controlled conditions in terms of environmental variables and contamination levels. O ur results indicate that exposure to endocrine disrupter compounds such as PCBs can induce anomalies in regeneration times, morphology and development al mechanisms that can be interpreted in the light of significant dysfuncti ons in the endocrine mechanisms controlling regenerative development.