Theodorakis This award supports Chrostopher Theodorakis and students from Texas Tech University in a collaboration with Rupert Simon of the National Research Center for Environment and Health in Neuherberg, Germany. The aim of the international project is to study the effect of thyroid-disrupting substance on molecular markers. The ecological relevance of these responses will be assessed in laboratory exposure experiments with zebrafish and African clawed frogs as fish and amphibian model species. The German group can provide samples of zebrafish exposed to selected pollutants, analyze them for thyroid hormones and iodinated compounds in tissue and serum samples, and determine exposure concentrations of organic contaminants in water and biological samples. The group at Texas Tech will expose zebrafish and African clawed frogs to perchlorate and analyze thyroid histology, analyze differential gene expression, and perform analysis of perchlorate in water and tissues. Results of the collaboration will develop new protocols for endocrine disrupting potential assessments of industrial and environmental chemicals. The work plan provides for extensive participation by graduate students in the international travel and research.