Figure 4.
Effects of gene GC content on gene coexpression relationships and regulation by alcohol abuse. A, ANOVA of average gene GC content (GC%) for 72 coexpression modules (labeled with brain region and module number) reveals remarkable heterogeneity among modules (F(71, 34,145) = 235; p < 10−500). B, Average gene GC% for 72 coexpression modules plotted versus average t values. A t value represents the magnitude and direction of alcohol effects (t < 0 indicates downregulation; t > 0 indicates upregulation by alcohol). Average gene GC% (C) and average GC% of Illumina probes (D) are plotted versus average gene expression values for the 72 coexpression modules (r = Pearson's correlation; n.s., not significant).