Induction of cytochrome P4501A (CYP1A) in Trematomus bernacchii as an indicator of environmental pollution in Antarctica: assessment by quantitative RT-PCR

Although most of Antarctica is relatively pristine, high levels of pollutan ts have been recorded in localised areas such as in the vicinity of scienti fic bases like McMurdo Station. We have used the Antarctic fish Trematomus bernacchii as an indicator species to assess the level of impact of these p ollutants on the local biota. Fish were collected from Winter Quarters Bay (adjacent to McMurdo Station) and Backdoor Bay (remote from human activitie s). Liver samples from individual fish were used in the preparation of tota l RNA from which the level of expression of the cytochrome P4501A gene (CYP 1A), known to be responsive to polycyclic aromatic hydrocarbons (PAHs), was determined by quantitative competitive reverse-transcriptase polymerase ch ain reaction (RT-PCR). Samples of bile from the same fish were analysed for fluorescent aromatic compounds (FACs) at naphthalene and phenanthrene wave lengths to provide an indication of exposure to organic compounds such as t he PAHs. The levels of biliary FACs in fish from Winter Quarters Bay were a pproximately 2-fold higher than those in fish from Backdoor Bay, whereas th ere was an average 37-fold increase in CYP1A expression between fish taken from the two sites. The extent of CYP1A induction correlated positively wit h biliary FACs levels, indicating the potential of quantitative competitive RT-PCR as a sensitive molecular approach to pollution impact assessment. F ish from Winter Quarters Bay also had significantly higher hepatosomatic an d gonadosomatic indices indicative of altered organ function, although the extent to which this might be related to pollution is uncertain. (C) 1999 E lsevier Science B.V. All rights reserved.