Reproductive and developmental abnormalities have been reported in the American alligator (Alligator mississippiensis) population from Lake Apopka, FL, that is chronically exposed to a complex mixture of environmental contaminants. To begin to understand the molecular mechanisms that could lead to the observed abnormalities of the reproductive and endocrine system, we quantified concentrations of the steroid hormones testosterone (T) and estradiol-17beta (E(2)) and expression of steroid hormone receptors and genes relating to steroidogenesis in gonadal tissue from juvenile alligators from three lakes in Florida using enzyme immunoassay and quantitative real-time polymerase chain reaction. Alterations of ESR2 (estrogen receptor beta) and SF1 (steroidogenic factor 1) mRNA expression in male gonadal tissue, without an observed difference in plasma concentrations of T, from the different lakes, begin to provide insight into potential mechanisms underlying the alterations of the reproductive system previously observed. Likewise, alterations in P450 aromatase and DAX1 (dosage-sensitive sex reversal, adrenal hypoplasia congenita critical region on the X chromosome, gene 1) mRNA expression, with elevated plasma E(2) concentrations in females, provide leads to the potential mechanisms modifying folliculogenesis and ovarian development. The investigation of these genes also helps clarify normal endocrine and reproductive system function in the American alligator.
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http://dx.doi.org/10.1016/j.aquatox.2008.03.006 | DOI Listing |
Biology (Basel)
December 2024
Department of Anatomy, Kirksville College of Osteopathic Medicine, Kirksville, MO 63501, USA.
This study was undertaken to explore the forces acting on the pes during pedal anchoring and to discern if pedal anchoring required the activation of the intrinsic pedal musculature. Replica feet equipped with strain gauges were moved over mud substrate, mimicking locomotion and pedal anchoring. Quantification of the substrate tracks demonstrated that they were similar to those made by freely moving , that the locomotor and pedal anchoring tracks were significantly different, and that the composition of the artificial feet significantly altered the tracks.
View Article and Find Full Text PDFJ Zoo Wildl Med
December 2024
Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH 43210, USA.
American alligators () are an important apex predator of semiaquatic habitats of the southern United States. Commercial alligator farming has grown in the last several decades, leading to a need to understand the health conditions that affect this species to ensure appropriate management and welfare. The aims of this study were 1) to establish and describe normative data including results of common ophthalmic diagnostic tests and conjunctival flora, 2) document ocular pathology in this population, and 3) assess the effect of topical rocuronium bromide and 10% phenylephrine for facilitating pharmacologic mydriasis.
View Article and Find Full Text PDFVet Pathol
December 2024
University of Florida, Gainesville, FL.
The American alligator () is a keystone species of the southeastern United States. In December of 2022, a free-ranging American alligator was found stuporous and tetraparetic. On postmortem evaluation, lesions were limited to the central nervous system, consisting of prominent perivascular cuffs of lymphocytes and histiocytes that extended into the surrounding neuroparenchyma along with gliosis.
View Article and Find Full Text PDFAnat Rec (Hoboken)
December 2024
Department of Anatomy, Kirksville College of Osteopathic Medicine, AT Still University, Kirksville, Missouri, USA.
J Anat
November 2024
Department of Anatomy, Kirksville College of Osteopathic Medicine, A.T. Still University, Kirksville, Missouri, USA.
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