Effects of Androgen and Paper Mill Effluent Exposure on Eastern Mosquitofish (Gambusia Holbrooki) Reproductive Health an...

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Material Information

Title:
Effects of Androgen and Paper Mill Effluent Exposure on Eastern Mosquitofish (Gambusia Holbrooki) Reproductive Health and Gene Expression Patterns
Physical Description:
1 online resource (186 p.)
Language:
english
Creator:
Brockmeier, Erica K
Publisher:
University of Florida
Place of Publication:
Gainesville, Fla.
Publication Date:

Thesis/Dissertation Information

Degree:
Doctorate ( Ph.D.)
Degree Grantor:
University of Florida
Degree Disciplines:
Veterinary Medical Sciences, Veterinary Medicine
Committee Chair:
DENSLOW,NANCY D
Committee Co-Chair:
BARBER,DAVID S
Committee Members:
ROBERTS,STEPHEN M
COHN,MARTIN J
PINE,WILLIAM E,III

Subjects

Subjects / Keywords:
androgen -- edc -- gonopodium -- mosquitofish
Veterinary Medicine -- Dissertations, Academic -- UF
Genre:
Veterinary Medical Sciences thesis, Ph.D.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract:
Endocrine disrupting compounds (EDCs) are chemicals that negatively impact endocrine system function, with effluent from paper mills one example of this class of chemical. In Florida, female Eastern mosquitofish (Gambusia holbrooki) are observed with male secondary sexual characteristics at three paper mill-impacted sites, indicative of EDC exposure. The objective of this project was to understand how androgen and paper mill effluent exposure impacts the phenotype of female mosquitofish and how this masculinization relates to reproduction by evaluating changes in gene expression. Exposure to the androgen 17ß-trenbolone (TB) induced anal fin elongation and the expression of three fin growth genes. Gene expression of the egg yolk precursor vitellogenin (vtg) was downregulated by a high dose of TB. There was no correlation between vtg and anal fin elongation. The full coding sequence for the gene sonic hedgehog (shh) was obtained and determined to be strongly related to shh of other fish. Shh was also constitutively expressed in sexually mature male G. holbrooki anal fins and downregulated during co-exposures with the anti-androgen flutamide. Results indicated that shh was a strong biomarker candidate of androgen exposure. Hepatic microarray analysis revealed the impact of TB exposure on genes involved in steroid biosynthesis and metabolism. Focused and global gene expression analyses of masculinized G.holbrooki from downstream of a paper mill were indicative of androgen exposure,while genes related to reproduction indicated a potential progestagenic exposure. Water samples collected downstream of the paper mill and a reference site indicated that progesterone receptor active chemicals were present at both and were therefore not the causative chemical at the paper mill impacted site.In addition, androgen and progesterone receptor (AR and PR) inhibitor studies revealed that anal fin elongation was driven by the AR and not PR. Results indicate that G. holbrooki downstream of the Fenholloway paper mill are impacted by androgens and progesterones. Molecular tools developed in this dissertation provide researchers the ability to conduct analyses on the molecular mechanisms of androgen exposure in this species. This research provides data of the mechanisms of how paper mill effluents in Florida are acting as endocrine disruptors.
General Note:
In the series University of Florida Digital Collections.
General Note:
Includes vita.
Bibliography:
Includes bibliographical references.
Source of Description:
Description based on online resource; title from PDF title page.
Source of Description:
This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility:
by Erica K Brockmeier.
Thesis:
Thesis (Ph.D.)--University of Florida, 2013.
Local:
Adviser: DENSLOW,NANCY D.
Local:
Co-adviser: BARBER,DAVID S.
Electronic Access:
RESTRICTED TO UF STUDENTS, STAFF, FACULTY, AND ON-CAMPUS USE UNTIL 2015-12-31

Record Information

Source Institution:
UFRGP
Rights Management:
Applicable rights reserved.
Classification:
lcc - LD1780 2013
System ID:
UFE0046179:00001