Correspondence analysis plot (A) and expression profiles of identified gene sets (B). Spots represent individual EST and vectors represents sample group trimmed means. Three groups of annotated genes after quality check are shown, representing the group 1 ("late genes") up-regulated from T2 (black spots or profiles respectively), the group 2 ("early genes") up regulated at T1 and subsequently down regulated (dark grey spots or profiles respectively) and the group 3 ("immediately early") genes up regulated in pre-ad II and subsequently down regulated (light grey spots or profiles respectively). Any gene located near the plot origin is poorly correlated with any of the principal axes and sampled groups. Correlation to both the principal axes and sample groups increases as genes are located further from the origin in the direction of one of the axes or sample group vectors.
Eichner et al. BMC Genomics 2008 9:126 doi:10.1186/1471-2164-9-126