It is demonstrated by DNA electrophoresis analysis, morphological obse
rvations and TdT in situ reaction, that Paracentrotus embryos if treat
ed with TPA plus heat undergo an apoptotic reaction. Indication is als
o obtained that non treated embryos undergo spontaneous apoptosis at t
he early pluteus stage, expecially in the districts of arms and intest
ine. The possible meaning of this latter observation is discussed. (C)
1997 Academic Press.