Variation within individuals (technical variance) and among individuals within populations and tissues (biological variance) for each of 192 genes indicated by the mean square error (MS) of measurements. Points above the dashed line indicate genes with greater variance among individuals than within. F-crit is the critical value of the F-statistic (F = MSamong/MSwithin, with 12 and 27 degrees of freedom and α = 0.05) for testing significant differences in gene expression between individuals. For 48% of genes, MSamong/MSwithin > F-crit (solid red line). These genes are therefore differentially expressed among individuals within treatments.
Whitehead and Crawford Genome Biology 2005 6:R13 doi:10.1186/gb-2005-6-2-r13