title: Developmental exposure to bisphenol A (BPA) alters sexual differentiation in painted turtles (Chrysemys picta).
abstract: Environmental chemicals can disrupt endocrine signaling and adversely impact sexual differentiation in wildlife. Bisphenol A (BPA) is an estrogenic chemical commonly found in a variety of habitats. In this study, we used painted turtles (Chrysemys picta), which have temperature-dependent sex determination (TSD), as an animal model for ontogenetic endocrine disruption by BPA. We hypothesized that BPA would override TSD and disrupt sexual development. We incubated farm-raised turtle eggs at the male-producing temperature (26°C), randomly assigned individuals to treatment groups: control, vehicle control, 17β-estradiol (E2, 20ng/g-egg) or 0.01, 1.0, 100μgBPA/g-egg and harvested tissues at hatch. Typical female gonads were present in 89% of the E2-treated "males", but in none of the control males (n=35). Gonads of BPA-exposed turtles had varying amounts of ovarian-like cortical (OLC) tissue and disorganized testicular tubules in the medulla. Although the percentage of males with OLCs increased with BPA dose (BPA-low=30%, BPA-medium=33%, BPA-high=39%), this difference was not significant (p=0.85). In all three BPA treatments, SOX9 patterns revealed disorganized medullary testicular tubules and β-catenin expression in a thickened cortex. Liver vitellogenin, a female-specific liver protein commonly used as an exposure biomarker, was not induced by any of the treatments. Notably, these results suggest that developmental exposure to BPA disrupts sexual differentiation in painted turtles. Further examination is necessary to determine the underlying mechanisms of sex reversal in reptiles and how these translate to EDC exposure in wild populations.
authors: Saint Louis Zoo Institute for Conservation Medicine, One Government Drive, St. Louis, MO 63110, United States; USGS Columbia Environmental Research Center, 4200 New Haven Rd, Columbia, MO 65201, United States; Bond Life Sciences Center, 1201 E. Rollins St., University of Missouri, Columbia, MO 65201, United States. Electronic address: cmjkwd@missouri.edu.
authors: Caitlin M
authors: CM
authors: Jandegian
authors: Saint Louis Zoo Institute for Conservation Medicine, One Government Drive, St. Louis, MO 63110, United States; Veterinary Medicine and Surgery, 1600 E. Rollins St., University of Missouri, Columbia, MO 65201, United States. Electronic address: deem@stlzoo.org.
authors: Sharon L
authors: SL
authors: Deem
authors: USGS Columbia Environmental Research Center, 4200 New Haven Rd, Columbia, MO 65201, United States; Biological Sciences, University of Missouri, Columbia, MO 65201, United States. Electronic address: Bhandarir@missouri.edu.
authors: Ramji K
authors: RK
authors: Bhandari
authors: Pathology and Anatomical Sciences, School of Medicine, One Hospital Drive, University of Missouri, Columbia, MO 65212, United States. Electronic address: Hollidayca@missouri.edu.
authors: Casey M
authors: CM
authors: Holliday
authors: USGS Columbia Environmental Research Center, 4200 New Haven Rd, Columbia, MO 65201, United States. Electronic address: dnicks@usgs.gov.
authors: Diane
authors: D
authors: Nicks
authors: Bond Life Sciences Center, 1201 E. Rollins St., University of Missouri, Columbia, MO 65201, United States; Biomedical Sciences, 1600 E. Rollins St., University of Missouri, Columbia, MO 65201, United States; Genetics Area Program, University of Missouri, Columbia, MO 65201, United States. Electronic address: RosenfeldC@missouri.edu.
authors: Cheryl S
authors: CS
authors: Rosenfeld
authors: Biological Sciences, Duquesne University, 600 Forbes Ave., Pittsburgh, PA 15282, United States. Electronic address: selcer@duq.edu.
authors: Kyle W
authors: KW
authors: Selcer
authors: USGS Columbia Environmental Research Center, 4200 New Haven Rd, Columbia, MO 65201, United States; Biological Sciences, University of Missouri, Columbia, MO 65201, United States. Electronic address: dtillitt@usgs.gov.
authors: Donald E
authors: DE
authors: Tillitt
authors: Biological Sciences, University of Missouri, Columbia, MO 65201, United States. Electronic address: vomsaalf@missouri.edu.
authors: Frederick S
authors: FS
authors: Vom Saal
authors: USGS Columbia Environmental Research Center, 4200 New Haven Rd, Columbia, MO 65201, United States. Electronic address: vvelez@usgs.gov.
authors: Vanessa
authors: V
authors: Vélez-Rivera
authors: Bond Life Sciences Center, 1201 E. Rollins St., University of Missouri, Columbia, MO 65201, United States. Electronic address: yangyin@missouri.edu.
authors: Ying
authors: Y
authors: Yang
authors: Pathology and Anatomical Sciences, School of Medicine, One Hospital Drive, University of Missouri, Columbia, MO 65212, United States; Biology and Environmental Science, Westminster College, 501 Westminster Ave, Fulton, MO 65251, United States. Electronic address: dawn.holliday@westminster-mo.edu.
authors: Dawn K
authors: DK
authors: Holliday
mesh_terms: D000818:Animals; D001559:Benzhydryl Compounds / Q000494:pharmacology*; D004958:Estradiol / Q000378:metabolism; D005260:Female; D016166:Free Radical Scavengers / Q000494:pharmacology*; D006066:Gonads / Q000187:drug effects / Q000254:growth & development*; D007124:Immunoenzyme Techniques; D008297:Male; D010636:Phenols / Q000494:pharmacology*; D012733:Sex Differentiation / Q000187:drug effects*; D046468:Sexual Development / Q000187:drug effects*; D013696:Temperature; D014426:Turtles / Q000254:growth & development* / Q000378:metabolism; D014819:Vitellogenins / Q000378:metabolism; D051176:beta Catenin / Q000378:metabolism; D000098826:Bisphenol A Compounds
chemical_list: D001559:Benzhydryl Compounds; D004958:Estradiol; D016166:Free Radical Scavengers; D010636:Phenols; D014819:Vitellogenins; D051176:beta Catenin; C006780:bisphenol A; D000098826:Bisphenol A Compounds
keywords: Aquatic reptile; Endocrine disrupting chemical; Feminization; SOX9; Vitellogenin; β-Catenin