Principal component analysis (PCA). A) PCA was performed for gene subsets with > 1.5-fold change in expression over the 28-day culture period (See Methods). The results are shown for the three major gene profiles generated by PCA. The red line represents the mean value of time-course changes (days 7, 14, 21 and 28). B) Expression values were normalized to the mean values of Day 7 samples. The resultant log2 ratios at each day were averaged and displayed in the heatmap. The color bar indicates log2 ratio of change in gene expression.
Li et al. BMC Genomics 2012 13:153 doi:10.1186/1471-2164-13-153