A. Tanguy et al., Effects of an organic pollutant (tributyltin) on genetic structure in the pacific oyster Crassostrea gigas, MAR POLL B, 38(7), 1999, pp. 550-559
Within the overall context of coastal ecosystem monitoring, the effects of
an organic pollutant (i.e. tributyltin) on the genetic structure of the Pac
ific oyster Crassostrea gigas along Brittany (France) coasts were studied i
n order to identify specific genetic indicators. Contamination experiments
were conducted using two concentrations of tributyltin (TBT). Electrophoret
ic analyses focused on sis enzyme loci and the results were analysed to dis
cern allozyme differences between samples. The survival curves obtained cle
arly reveal the high toxicity of TBT on adult oysters. Electrophoretic data
also highlighted the existence of allozymes which can be used as putative
genetic indicators of TBT contamination. It would appear that the following
enzyme systems, aspartate-amino-transferase (Aat-2), adenylate kinase (Ak)
and phosphoglucomutase (Pgm) are involved in the main physiological proces
ses affected by tributyltin; allozymes of these loci are characterized by f
requencies which vary significantly between TBT-resistant and more TBT-sens
itive adults. These data reflect the adaptive nature of certain allozymes a
nd show that relatively simple methods associated with an appropriate biolo
gical material may be a powerful tool to assess the effects of pollutants o
n marine invertebrates. (C) 1999 Elsevier Science Ltd. All rights reserved.