Abstract:
Increased contamination of waterways has lead to many impacts on organisms, including effects on reproduction. A suite of
endocrine-disruptive chemicals CEDC's) has been shown to mimic sex hormones in vertebrates and their presence is an important
bioindicator of environmental degradation. We examined the expression of vitellogenin (Vtg, a female yolk protein) in male
toadfish (Tetractenos glaber), as an indicator of EDC presence in estuaries around Sydney, Australia. First, we demonstrated
the induction of Vtg in males from unpolluted estuarine sites through injection of 17-B-oestradio1. Secondly, the presence of
Vtg in the serum offish from polluted and unpolluted estuaries was investigated by reducing-po1yacryamide gel electrophoresis
(SDS-PAGE). While females from polluted (downstream from sewage treatment plants, and subject to urban runoff) and less
polluted sites all expressed Vtg in blood serum, males from less polluted sites showed little or no evidence of Vtg expression.
However, most males from heavily polluted sites showed moderate to high levels of Vtg expression, indicating that EDC's
were present and affecting normal endocrine function in males.
We suggest that simple biochemical examinations ofEDC effects, such as Vtg induction in males, are useful rapid assessment
methods which can provide evidence upon which, further more detailed studies may be undertaken.
