Regeneration in Hydrozoa: distal versus proximal transformation inHydractinia
Muller, W.A.; Plickert, G.; Berking, S.
Development Genes and Evolution 195(8): 513-518
ISSN/ISBN: 0949-944X DOI: 10.1007/bf00375892
Polyps of mature colonies of Hydractinia echinata obey the "rule of distal transformation" by regenerating heads but not stolons. However, this rule is not valid for young polyps as these regenerate stolons from proximal cut ends. Also, small cell aggregates and even small fragments excised from full-grown polyps are capable of stolon formation. Aggregates produced from dissociated cells undergo either distal or proximal transformation depending on their size, speed of head regeneration in the donor used for dissociation and the positional derivation of the cells. The latent capability of stolon formation is released under conditions that cause loss of morphogens and depletion of their sources.