Cross-experiment validation of leaf development candidate transcription factors and modules. A-D Expression of selected transcription factors with developmental expression patterns in four Populus microarray experiments (Seasonal data of , UPSC-TC experiment, UPSC-LP experiment, Pt-TC experiment) and of the best BLAST hit ortholog in the Arabidopsis AtGenExpress developmental baseline experiment . The genes are gw1.VII.2982.1, estExt_Genewise1_v1.C_290455, gw1.XII.82.1, gw1.41.334.1 respectively. E-F Expression of the most highly-connected gene for transcriptional modules with a developmental expression trend identified by Topological Overlap Matrix weighted co-expression analysis. Genes are coloured based on their module colour in Figure 4. Blue, estExt_fgenesh4_pm.C_LG_V0721; Red, estExt_fgenesh4_pg.C_LG_XII1021; Green, estExt_fgenesh4_kg.C_LG_X0057; Turquoise, estExt_fgenesh4_pg.C_440087.