Wnt signalling components do not cycle in chick PSM. (A, G, H) Intronic and (B) Exonic probes to cNkd1 and cLef1 show a gradient of PSM expression. (B, H) Fix and culture assays, where explants of the caudal embryo are bisected down the midline, following which both sides are cultured for 15 min minimum and then one explant fixed while the other was cultured for 45 min longer, confirms absence of oscillatory expression for both genes. (C, D) Intronic cAxin2 expression is restricted to the caudal PSM. (D) The fix and culture assays showed no dynamism in expression. (E, F) Exonic cDact1 expression is restricted to the rostral PSM. (F) The fix and culture assays showed no dynamism in expression.