Difference between revisions of "Compute differentially expressed genes (Agilent Tox probes) (workflow)"

Revision as of 12:21, 25 August 2015

Workflow title

Compute differentially expressed genes (Agilent Tox probes)

Provider

geneXplain GmbH

Workflow overview

Description

This workflow is designed to identify up-regulated, down-regulated and non-changed genes for experimental data with three and more data points for each experiment and control.  

As input, normalized data with Agilent probeset IDs can be submitted. Such normalized files are the output of the “Normalize data” procedure.

In the next step, p-values for up- and down- regulated probes are calculated for all probes using the “Up and Down Identification” analysis,. This analysis applies Student’s T-test for p-value calculation, thus the number of data points should be at least three for each experiment and control. 

Simultaneously, the log fold change is calculated for each probeset ID, resulting in  a table in which both log fold changes and p-values are assigned to each probeset ID. A histogram with log fold change distribution is calculated and generated as one of the output files.

In addition, this table is filtered by several conditions in parallel applying the “Filter table” method, to identify up-regulated, down-regulated, and non-changed Agilent probeset IDs. The filtering criteria are set as follows:

For up-regulated probes: LogFoldChange>0.5 and -log_P_value_>3.

For down- regulated probes: LogFoldChange<-0.5 and -log_P_value_<-3.

For non-changed genes : LogFoldChange<0.002 and LogFoldChange>-0.002

The resulting tables of the up-regulated, down-regulated, and non-changed Agilent probeset IDs are converted into a gene set via the “Convert table” method and annotated with additional information, gene descriptions, gene symbols, and species via “Annotate table”. Two tables are produced, with Ensembl Gene IDs and with Entrez IDs. 

A new folder is generated as output containing Ensemble and Entrez gene tables for up-regulated, down-regulates, up- and down-regulated together, and non-changed genes. After completion of the workflow, a script generates a report which gives the summary of the workflow output files. 

Parameters

Experiment normalized

Control normalized

Species

Results folder