In an experiment to identify genes of the plant Arabidopsis that react to a particular pathogen, researchers used RNA sequencing to produce gene profiles for a number of plants not subjected to the pathogen and several plants subjected to the pathogen. Tests comparing the distribution of gene expression in the two groups were performed for each gene individually. The data are the p-values from all these tests. The goal is to use a identify a set of genes that differentially express in the two groups, subject to some specified value for expected false discovery rate, such as 5%.
ex1620A data frame with 20,245 observations on the following 3 variables.
an identification number for genes
a character variable with the name of the gene
the p-value from a test that the mean expression level for the gene differs in the two groups (ignoring multiple testing)
Chang, J, Department of Botany and Plant Pathology, Oregon State University, personnal communication.