Gene expression response in target organ and whole blood varies as a function of target organ injury phenotype

Histopathology, clinical chemistry, hematology and gene expression data were collected from the rat liver and blood after treatment with eight known hepatotoxins

Hepatic Gene Expression Changes throughout the Day in the Fischer Rat: Implications for Toxicogenomic Experiments

There is increasing use of transcriptional profiling in hepato-toxicity studies in the rat. Understanding hepatic gene expression changes over time is critical, since tissue collection may occur throughout the day. Furthermore, when comparing results from different data sets, times of dosing and tissue collection may vary. Circadian effects on the mouse hepatic transcriptome have been well documented. However, limited reports exist for the rat. In one study approximately 7 % of the hepatic genes showed a diurnal expression pattern in a comparison of rat liver samples collected during the day versus livers collected at night. The results of a second study comparing rat liver samples collected at multiple time points over a circadian day suggest only minimal variation of the hepatic transcriptome. We studied temporal hepatic gene expression in 48 untreated F344/N rats using both approaches employed in these previous studies. Statistical analysis of micro

Hierarchical clustering of animals in the low dose/6 hour group using SVM-derived classifiers

Two-way hierarchical clustering using Ward's minimum variance as the heuristic criteria and Euclidean distance as the similarity metric was performed on all of the animals in the low dose/6 hour group using the blood expression values for the 160 transcripts identified as compound classifiers for this dose/time group by a SVM algorithm. The degree of relatedness between each sample is represented by the dendrogram (hierarchical tree) presented in this figure, wherein the height of each branch represents the distance between the two objects being connected.<p><b>Copyright information:</b></p><p>Taken from "Gene expression response in target organ and whole blood varies as a function of target organ injury phenotype"</p><p>http://genomebiology.com/2008/9/6/R100</p><p>Genome Biology 2008;9(6):R100-R100.</p><p>Published online 20 Jun 2008</p><p>PMCID:PMC2481421.</p><p></p

Hierarchical clustering of animals in the medium dose/6 hour group using SVM-derived classifiers

Two-way hierarchical clustering using Ward's minimum variance as the heuristic criteria and Euclidean distance as the similarity metric was performed on all of the animals in the medium dose/6 hour group using the liver expression values for the 160 transcripts identified as compound classifiers for this dose/time group by a SVM algorithm. The degree of relatedness between each sample is represented by the dendrogram (hierarchical tree) presented in this figure, wherein the height of each branch represents the distance between the two objects being connected.<p><b>Copyright information:</b></p><p>Taken from "Gene expression response in target organ and whole blood varies as a function of target organ injury phenotype"</p><p>http://genomebiology.com/2008/9/6/R100</p><p>Genome Biology 2008;9(6):R100-R100.</p><p>Published online 20 Jun 2008</p><p>PMCID:PMC2481421.</p><p></p