Fig. 4. Effects of head and foot regeneration induced in the parent on bud development and kringelchen expression. (A-G) Head regeneration and bud development [bud stages according to Otto and Campbell (Otto and Campbell, 1977)]. (A) Competition of both processes results in failure of bud detachment if regeneration is induced early in budding (n=100). (B-G) Expression pattern of kringelchen if the parent head is removed immediately above a stage 3 bud: (B) 10 hours, (C) 26 hours, (D) 22 hours, (E) 31 hours, (F) 36 hours, (G) 57 hours. (H-L) Effect of foot regeneration on bud development. (H) Detachment of the young polyp is slightly accelerated (n=100 each). (I-L) Expression pattern of kringelchen after foot removal immediately below a stage 3 bud, evaluation about 24-25 hours after cutting. The typical ring is present and broader than in normal buds.