5/11/98

The following research article appears in Environmental Science & Technology

http://acsinfo.acs.org/subscribe/journals/esthag/browse_asap.html

Photoproducts and Metabolites of a Common Insect Growth Regulator Produce Developmental Deformities in Xenopus

James J. La Clair,* John A. Bantle, and James Dumont Department of Molecular Biology, The Scripps Research Institute, 10550 N. Torrey Pines Rd. La Jolla, California 92037 and the Department of Zoology, Oklahoma State University, 430 Life Sciences West, Stillwater, Oklahoma 74078

Abstract: In the past decade, numerous sights across North America have been found which contain abnormal levels of deformed amphibians. This deformation was not limited to species, geography, or climate and spanned a wide range of phenotypes. This report begins to explain these findings by examining the effects of pesticide degradation in early amphibian development through directly exposing Xenopus laevis embryos to trace levels of synthetically prepared degradates. This method specifically determines the risk posed by each individual chemical resulting from the natural fate of the host pesticide. Through this approach, we find that while the common insect growth regulator, S-methoprene, poses minimal developmental determent, products of its reaction with sunlight, water, and microorganisms dramatically interfere with normal amphibian development. The addition of 1 L/L of several of S-methoprene's degradates to the environment of developing embryos resulted in juveniles with deformation similar to that found naturally. Current developmental assessments examine only the risk posed by host pesticides. This study now suggest that the simple examination of the these materials is not sufficient, but now forward the need for critically examining the temporal relation between both development and chemical degradation.