Screening California surface waters for estrogenic endocrine disrupting chemicals (EEDC) with a juvenile rainbow trout liver vitellogenin mRNA procedure

Abstract

Concern regarding the occurrence of chemicals that disrupt endocrine system functions in aquatic species has heightened over the last 15 years. However, little attention has been given to monitoring for estrogenic endocrine disrupting chemicals (EEDCs) in California's freshwater ecosystems. The objective was to screen surface water samples for estrogenic activity using vitellogenin (Vtg) mRNA quantification in livers of juvenile rainbow trout by real-time reverse transcriptase polymerase chain reaction (Q-RT PCR). Vtg mRNA analysis of livers from fish exposed to 113 ambient water samples collected from surface waters in California's Central Valley and northern area indicated that six samples (5% of total) may have contained EEDCs. The six samples induced marginal, but statistically significant, increases of Vtg mRNA. No ambient water sample evoked Vtg mRNA responses equivalent to those in positive controls (all responses were less than 2% of the positive control response). Thus, EEDC concentrations in these samples were low (at or near the threshold for the procedure) or results may have included false positives. To establish a more definitive assessment of EEDC occurrence, follow-up screening at sites where statistically significant, but weak, estrogenic activity was observed is recommended. Overall, results reveal that a majority of the California surface waters tested were below EEDC detection threshold concentration for the screening procedure utilized.

Exposure to Bisphenol AF disrupts sex hormone levels and vitellogenin expression in zebrafish

“…However, the synthesis of VTG in adult male fish can be induced by the presence of estrogenic compounds (Jin et al, ). Thus, the induction of VTG gene expression in males or larvae has been used as a sensitive biomarker for estrogenic disruption in oviparous organisms (Zhang et al, ; Miller et al, ; de Vlaming et al, ). Expression of VTG is under the control of 17β‐estradiol, which can bind to specific endocrine receptors (ERs) in response to the stimulation of endocrine‐disrupting chemicals (Verderame and Limatola, ).…”

Exploring the Impacts of Two Separate Mixtures of Pesticide and Surfactants on Estrogenic Activity in Male Fathead Minnows and Rainbow Trout

“…The continued exposure to these lowlevel mixtures of endocrine-disrupting compounds could potentially affect fish populations that spend at least part of their life history in areas with known anthropogenic pollutants such as the San Francisco Bay Delta (SF Delta) (Davis et al 2007;Diehl et al 2012). Recent studies have identified a number of estrogenic and antiandrogenic compounds in surface waters of the Central Valley and SF Delta (de Vlaming et al 2007;Lavado et al 2009;Brander et al 2013). In vitro bioassay-guided fractionation analyses of SF Delta water using rainbow trout (RT; Oncorhynkus mykiss) hepatocytes showed that alkylphenol ethoxylates, alkylphenols, and certain pesticides have co-occurred in fractions with increased estrogenic activity measured as expression of hepatic vitellogenin (VTG) protein (Lavado et al 2009).…”

Molecular Cloning and Characterization of the Expression Profiles of Vitellogenin Transcripts in the Dojo Loach (Misgurnus anguillicaudatus) in Response to 17α-Ethinylestradiol and 17β-Estradiol Administration

“…The impact of EDCs on fish has been evaluated and studied extensively (De Vlaming et al, 2007). The dojo loach (Misgurnus anguillicaudatus) is a widespread freshwater fish in East Asia.…”