BioProject

Masculinized female Eastern Mosquitofish (Gambusia holbrooki) have resided downstream of paper mills in Florida since the 1980's. More...

Masculinized female Eastern Mosquitofish (Gambusia holbrooki) have resided downstream of paper mills in Florida since the 1980's. The potential impacts of this effluent on the mosquitofish endocrine system are unknown. The objective of this study was to evaluate gene expression patterns of endocrine system genes and global gene expression patterns in female G. holbrooki from a paper mill-impacted site. Masculinized female G. holbrooki were collected from a paper mill-impacted site (Fenholloway River) and from a reference site (Econfina River) and microarray analysis in livers was conducted. Hepatic microarray analysis revealed an increase in the expression of metabolic genes at the Fenholloway, with similarities in individual genes and biological processes compared to G. holbrooki exposed to androgens. These data indicate G. holbrooki from the Fenholloway may be impacted by a mixture of endocrine-active chemicals, including androgens. Overall design: During the summer of 2012, G. holbrooki were captured from one site downstream of the Buckeye Pulp and Paper Mill (Taylor County, Perry, FL, USA) on the Fenholloway River (GPS coordinates: N 30 058.341’, W 83 588.569’) and one site in the Econfina conservation area (GPS coordinates: N 30 08.549', W 83 51.962') . Only sexually mature G. holbrooki (females > 15cm standard length and with the presence of the gravid spot near the vent) were collected. A 1/8 mesh seine was used for sample collection. Female G. holbrooki were transferred to 5 gallon aerated buckets filled with site water and were processed at the site immediately after collection. Fish were anesthetized using Tricaine-S (Western Chemical, Ferndale, USA) and sacrificed via spinal transection. Oocyte development was assessed upon dissection and livers were removed and stored in RNAlater (Qiagen, Hilden, Germany) overnight at 4 C before storage at -80 C. RNA was isolated from the livers using TRIzol (Invitrogen, Grand Island, USA), hydrated using RNAsecure (Ambion, Grand Island, USA), and DNase treated using the Turbo DNA-free kit (Ambion, Grand Island, USA). Four oocyte-development stage-matched RNA samples per treatment were evaluated for RNA integrity using the 2100 BioAnalyzer (Agilent, Santa Clara, USA). The range of RIN values was 7.8-8.9. Less...