Toxicogenomics as a rational approach to endocrine disruptor research workshop session.

Temporal responses to estrogen in the uterus.

Fertuck KC.

Department of Biochemistry & Molecular Biology, National Food Safety & Toxicology Center, and Institute for Environmental Toxicology, Michigan State University, East Lansing, MI.

The estrogen receptor acts primarily as an estrogen-inducible transcription factor in target organs, however until recently the identification of individual responsive transcripts has been cumbersome. In the present study oligonucleotide GeneChip microarrays were used to describe and analyze the levels of approximately 6,500 transcripts in the uteri of immature, ovariectomized mice at various times following oral exposure to 100 ?g/kg of ethynyl estradiol. The most reproducible responses were identified and subjected to K-means clustering, and functional annotations were obtained for the transcripts within each cluster. Connections were made between the observed transcriptional responses and the known physiological responses to estrogen exposure, focusing here on effects on uterine cell cycle progression leading to estrogen-stimulated uterine growth.