Meeting Abstract
17.4 Monday, Jan. 4 A timecourse study in embryonic development of African dwarf frogs Hymenochirus boettgeri exposed to atrazine STAHL, A.L.*; OLSON, W.M.; University of Northern Iowa; University of Northern Iowa aarons@uni.edu
Stahl, Aaron A timecourse study in embryonic development of African dwarf frogs Hymenochirus boettgeri exposed to atrazine Atrazine is one of the most commonly used broad-leaf herbicides in the world. It functions by binding to a protein in photosystem II and inhibits electron transport. Previous studies have indicated that vertebrates exposed to atrazine display consequences such as behavioral changes, endocrine disruption, and delayed development. The focus of this study is to determine the effect of atrazine on embryonic developmental rate of the African dwarf frog. It has been proposed that development can be slowed due to decreased cyclin levels caused by exposure to atrazine. Cyclin levels must reach a threshold to progress the cell through mitosis. The first study focused on embryonic development from fertilization to 72 hours after hatching. In this experiment eggs were collected immediately after fertilization. Half of the eggs were exposed to three different quantities of atrazine: 10 ppb, 5 ppb, and 1 ppb. Eggs not exposed to atrazine were used as a control. Specimens were analyzed for morphological abnormalities and changes in developmental rate; some were also stained for the analysis of neuromuscular junctions. The second study examined G1 cyclin levels. Cellular synchronization was achieved by amputating the right hindlimb of tadpoles at stages 52 to 54. The limb was allowed to regenerate over a period of 14 to 20 days in the three different quantities of atrazine and a control. After the regeneration period morphological features of the organism and the limb bud were analyzed. The regenerated limb buds were amputated and homogenized to extract nuclear proteins. Extractions were used in a sandwich ELISA for quantification of the G1 cyclins. Preliminary results will be presented.
