Fig. 4. hydkk1/2/4 expression during budding and regeneration. (A) Early to late developing bud stages; (B) head regeneration. Polyps were decapitated at 80% body length and allowed to regenerate for the times indicated; arrows indicate the cutting position to isolate regenerating tips for quantification (see text). (C) Quantification of hydkk1/2/4-expression dynamics in regenerating tips. Expression in the apical 10% of body length was determined (n=14 to 24 polyps per sample): dark bars represent animals with hydkk1/2/4 upregulation, light bars represent silenced hydkk1/2/4 expression. (D,E) hydkk1/2/4 expression in macerated cells. bc, cells of normal body column tissue; reg, cells from regenerating tissue.