Fig. 3. Whole-mount in situ hybridization for hydra laminin ß1 chain (LM), hydra type I collagen (Col), and hydra matrix metalloproteinase (MMP) mRNA monitored at 24, 48 and 72 hours after decapitation. The progression of the in situ signal (arrows) for LM, Col and MMP mRNA over this time frame changes from a general signal along the apical pole at 24 hours (A,D,G) to one associated with erupting tentacles at 48 hours (B,E,H) and 72 hours (C,F,I). Scale bar: 250 µm.