title: Endogenous and exogenous estrogens during embryonic development affect timing of hatch and growth in the American alligator (Alligator mississippiensis).
abstract: Prenatal exposure to estrogenic endocrine disrupting chemicals (EDCs) can affect length of gestation and body mass and size of offspring. However, the dose, timing, and duration of exposure as well as sex and strain of the experimental animals determine the direction and magnitude of these effects. In this study, we examined the effects of a one-time embryonic exposure to either 17 β-estradiol (E2) or bisphenol A (BPA) on rate of development and growth in American alligators (Alligator mississippiensis). Our results indicate that BPA and E2-treated alligators hatched approximately 1.4 days earlier than vehicle-treated (control) alligators, suggesting that estrogenic chemicals hasten hatching in these animals. We assessed growth rates, growth allometry, and body condition for 21 weeks after hatching and found that BPA-treated alligators grew more quickly shortly after hatching but more slowly thereafter compared to control alligators. Conversely, E2-treated alligators grew more slowly shortly after hatching but more quickly thereafter compared to control alligators. As a result of differences in growth rate, BPA-treated alligators were heavier, longer, and fatter than control alligators at age 5 weeks but were similar in size and leaner than control alligators at age 21 weeks. Biochemical analytes were examined at the end of the 21-week study to assess overall metabolic condition. We found that E2-treated alligators had significantly higher circulating plasma concentrations of cholesterol and triglycerides than control alligators while BPA-treated alligators had blood profiles comparable to control alligators. Our results provide important insights into the effects of exogenous estrogens on morphology and metabolism in an oviparous, semi-aquatic reptile.
authors: Department of Biology, University of Florida, 220 Bartram Hall, Gainesville, FL 32610, USA. Electronic address: cruzel@musc.edu.
authors: Lori
authors: L
authors: Cruze
authors: Department of Biology, Furman University, 3300 Poinsett Highway, Greenville, SC 29613, USA.
authors: Alison M
authors: AM
authors: Roark
authors: Department of Biology, University of Florida, 220 Bartram Hall, Gainesville, FL 32610, USA.
authors: Gabrielle
authors: G
authors: Rolland
authors: Department of Biology, University of Florida, 220 Bartram Hall, Gainesville, FL 32610, USA.
authors: Mona
authors: M
authors: Younas
authors: Department of Large Animal Clinical Sciences, University of Florida, College of Veterinary Medicine, 2015 SW 16th Ave, Gainesville, FL 32610, USA.
authors: Nicole
authors: N
authors: Stacy
authors: Department of Biology, University of Florida, 220 Bartram Hall, Gainesville, FL 32610, USA.
authors: Louis J
authors: LJ
authors: Guillette
mesh_terms: D000489:Alligators and Crocodiles / Q000196:embryology / Q000254:growth & development* / Q000378:metabolism; D000818:Animals; D001559:Benzhydryl Compounds / Q000378:metabolism*; D047108:Embryonic Development; D004958:Estradiol / Q000378:metabolism*; D004967:Estrogens / Q000378:metabolism*; D010636:Phenols / Q000378:metabolism*; D000098826:Bisphenol A Compounds
chemical_list: D001559:Benzhydryl Compounds; D004958:Estradiol; D004967:Estrogens; D010636:Phenols; C006780:bisphenol A; D000098826:Bisphenol A Compounds
keywords: Bisphenol A; Disruption; Endocrine; Growth; Metabolism