Tetrahymena thermophila is a model eukaryotic organism. Functional genomic analyses in Tetrahymena present rich opportunities to address fundamental questions of cell and molecular biology. The Tetrahymena Gene Expression Database (TGED; available at http://tged.ihb.ac.cn) is the first expression database of a ciliated protozoan. It covers three major physiological and developmental states: growth, starvation, and conjugation, and can be accessed through a user-friendly web interface. The gene expression profiles and candidate co-expressed genes for each gene can be retrieved using Gene ID or Gene description searches. Descriptions of standardized methods of sample preparation and the opportunity to add new Tetrahymena microarray data will be of great interest to the Tetrahymena research community. TGED is intended to be a resource for all members of the scientific research community who are interested in Tetrahymena and other ciliates.
Dichlorodiphenyltrichloroethane (DDT),tributyltin (TBT),and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) are persistent in the environment and cause continuous toxic effects in humans and aquatic life.Tetrahymena thermophila has the potential for use as a model for research regarding toxicants.In this study,this organism was used to analyze a genome-wide microarray generated from cells exposed to DDT,TBT and TCDD.To accomplish this,genes differentially expressed when treated with each toxicant were identified,after which their functions were categorized using GO enrichment analysis.The results suggested that the responses of T.thermophila were similar to those of multicellular organisms.Additionally,the context likelihood of relatedness method (CLR) was applied to construct a TCDD-relevant network.The T-shaped network obtained could be functionally divided into two subnetworks.The general functions of both subnetworks were related to the epigenetic mechanism of TCDD.Based on analysis of the networks,a model of the TCDD effect on T.thermophila was inferred.Thus,Tetrahymena has the potential to be a good unicellular eukaryotic model for toxic mechanism research at the genome level.
