| Application of Ecotoxicogenomics for Studying Endocrine Disruption
in Vertebrates and Invertebrates Taisen Iguchi, Hajime Watanabe, and Yoshinao Katsu Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, Myodaiji, Okazaki, Japan; Department of Molecular Biomechanics, School of Life Science, Graduate University for Advanced Studies, Okazaki, Japan; Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Corporation, Kawaguchi, Japan Abstract
Chemicals released into the environment potentially disrupt the endocrine system in wild animals and humans. Developing organisms are particularly sensitive to estrogenic chemicals. Exposure to estrogens or estrogenic chemicals during critical periods of development induces persistent changes in both reproductive and nonreproductive organs, including persistent molecular alterations. Estrogen-responsive genes and critical developmental windows of various animal species, therefore, need to be identified for investigators to understand the molecular basis of estrogenic activity during embryonic development. For investigators to understand molecular mechanisms of toxicity in various species, toxicogenomics/ecotoxicogenomics, defined as the integration of genomics (transcriptomics, proteomics, metabolomics) into toxicology and ecotoxicology, need to be established as powerful tools for research. As the initial step toward using genomics to examine endocrine-disrupting chemicals, estrogen receptors and other steroid hormone receptors have been cloned in various species, including reptiles, amphibians, and fish, and alterations in the expression of these genes in response to chemicals were investigated. We are identifying estrogen-responsive genes in mouse reproductive tracts using cDNA microarrays and trying to establish microarray systems in the American alligator, roach, medaka, and water fleas (Daphnia magna) . It is too early to define common estrogen-responsive genes in various animal species ; however, toxicogenomics and ectotoxicogenomics provide powerful tools to help us understand the molecular mechanism of chemical toxicities in various animal species. Key words: alligator, Daphnia magna, ecotoxicogenomics, estrogen receptor, mosquitofish, mouse, roach, xenopus. Environ Health Perspect 114(suppl 1) :101-105 (2006) . doi:10.1289/ehp.8061 available via http://dx.doi.org/ [Online 21 October 2005]
This article is part of the monograph “The Ecological Relevance of Chemically Induced Endocrine Disruption in Wildlife.” Address correspondence to T. Iguchi, Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institute of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki 444-8787, Japan. Telephone: 81 564 59 5235. Fax: 81 564 59 5236. E-mail: taisen@nibb.ac.jp We thank L. Guillette, University of Florida at Gainesville, Florida, USA, for his critical reading of this manuscript. This study was supported in part by a grant-in-aid for scientific research from the Ministry of Education, Culture, Sports, Science, and Technology of Japan ; a health sciences research grant from the Ministry of Health, Labour and Welfare, Japan ; and a research grant from the Ministry of Environment, Japan. The authors declare they have no competing financial interests. Received 31 January 2005 ; accepted 25 August 2005. The full version of this article is available for free in HTML or PDF formats. |
