Gonadal histology and reproductive steroidogenesis in Lithobates pipiens exposed to atrazine

Abstract

Atrazine, an endocrine-disrupting compound and environmental pollutant, can have adverse effects on amphibian reproductive development and function. To determine the effects of atrazine on anuran gonadal development, Lithobates pipiens larvae were exposed from Gosner stage 25 through 1-month post metamorphosis to 0, 2, 20, or 200 μg/L atrazine or estradiol. Exposure to atrazine did not markedly alter tadpole growth, development, gonadal histology, or reproductive steroidogenesis. Testicular ovarian follicles appeared in L. pipiens metamorphs following all treatments, including controls, whereas ovotestes occurred only in positive controls. Testicular ovarian follicles may be a natural ontogenetic occurrence in this species while ovotestes indicate disruption in development. Establishing the normal pattern of reproductive development for anuran species and conducting comparisons in fully sexually differentiated animals is necessary to clarify the influence of endocrine disrupting compounds.

Keywords:

• Atrazine
• anuran
• frog
• reproductive
• endocrine

Acknowledgments

The authors thank L. Dow and D. Adams for assistance with animal husbandry and S. Kavanaugh, L. Dow, and L. Plagge for assistance with data collection. We thank F. Pinkney, P. Tsang, and J. Bolker for helpful comments on early drafts of this manuscript. All procedures were reviewed and approved by the University’s Animal Care and Use Committee.

Disclosure statement

No potential conflict of interest was reported by the authors. The views expressed in the article are those of the authors and do not reflect official policy of the Department of the Army, Department of Defense, or the U.S. Government.

Additional information

Funding

This research was supported by the U.S. Environmental Protection Agency’s Science to Achieve Results (STAR) fellowship program [grant number U-91616201 to EML]. Although the research described in the article has been funded wholly or in part by the U.S. Environmental Protection Agency's STAR program, it has not been subjected to any EPA review and therefore does not necessarily reflect the views of the Agency, and no official endorsement should be inferred.