Induction of cypris major protein in barnacle larvae by exposure to 4-n-nonylphenol and 17 beta-oestradiol

Intense efforts are currently being made to develop procedures to assess th e potential for endocrine disruption in aquatic environments. Most attentio n has focused on fresh water systems, amphibians and fish and morphological and molecular measures for endocrine disruption. A biomarker approach invo lving the induction of a female-specific protein, vitellogenin, in males by exposure to xeno-oestrogens has proved particularly useful. By contrast ma rine environments and invertebrates have received comparatively little atte ntion. The present study aimed to examine the effects of exposure to a xeno -oetrogen, 4-n-nonylphenol (4-NP) and a natural oestrogen, 17 beta-oestradi ol (E-2) on a marine crustacean, the barnacle Balanus amphitrite. In partic ular, the effect of such exposure on levels of a larval storage protein, cy pris major protein (CMP), which is related to barnacle vitellin, has been e xamined. Accordingly, nauplius stage larvae of B. amphitrite were exposed t o low concentrations (0.01-1.0 mu g l(-1)) of 4-NP and E-2 (1.0 mu g l(-1)) from egg hatching until the cypris stage. SDS-PAGE and immunoblotting were used to monitor CMP levels in exposed larvae relative to 'zero' concentrat ion controls. Elevated (100% increase) CMP levels were measured in larvae e xposed to both 4-NP and E-2 at a concentration of 1.0 mu g l(-1), and notab le increases occurred at lower concentrations of 4-NP. It is concluded that CMP and perhaps other vitellin-like proteins are potential biomarkers of l ow level oestrogen exposure in crustaceans. (C) 2000 Elsevier Science B.V. All rights reserved.