Primary microarray analysis.

(A) Principal components analysis. Expression profiles are plotted in the space of the 1st and 2nd principal components, which account for 40% and 37% of the total variance, respectively. Red/green depicts samples from PFO (red) and PT (green) areas; fill/empty symbols, 17/19 GW; circles/square symbols, right/left. (B) Summary of gene profiling results depicting the number of genes displaying a fold change higher than 1.5 for found at 17 or 19 GW (PFO>PT in red; PT>PFO in green); genes displaying a fold change higher than 1.5 for PFO vs. PT at both 17 GW and 19 GW (intersection of genes displaying differential regulation between PFO and PT at either 17 or 19 GW)) are depicted within the central vertical thick arrow. The number of genes displaying a fold change higher than 1.5 for 17 vs. 19 GW found in PFO or PT (17GW>19GW in blue; 17GW<19GW in gray); genes displaying a fold change above 1.5 for 17 vs. 19 in both PFO and PT are shown in the bottom blue and gray thick arrow.