Fig. 2

Homeobox family transcription factors (TFs) upregulated upon activation of Wnt signalling are expressed in head (oral side) of the polyp. Hierarchical clustering of differentially expressed TFs was carried out and domain organization of the upregulated TFs was studied. Expression analysis of selected TFs was carried out by in situ hybridization. a Heatmap of differentially expressed TFs after activation of Wnt signalling. VC.1, VC.2, biological replicates of vehicle (DMSO) controls; ALP.1, ALP.2, biological replicates of Alsterpaullone (5 μM)-treated samples; intensity of red and blue colours indicates respectively the higher and lower expression levels of genes compared to the controls; red and blue colours denote significantly up- and downregulated genes with log₂ fold change cut-off of ±0.58 with a p value of 0.01, respectively; genes that have been previously reported and characterized in Hydra are labelled in black and genes investigated in the current study are labelled in green. b Domain organization of TFs upregulated by Wnt signalling. c Expression pattern of HvOtp1, HvOtx1, Margin and Gorget and magnified images of selected regions of the polyps displaying expression. Scale bar represents 100 µm. d Expression pattern of HvOtp1, HvOtx1, Margin and Gorget in DMSO controls and Alsterpaullone (5 µM)-treated polyps. Scale bar represents 200 µm.