RESUMO
The diploblastic Hydra is among the most primitive multicellular organisms. Using cross-hybridization with Xenopus probes, noggin-like transcripts were detected in the hypostome and basal disc of adult Hydra (Pelmatohydra oligactis), regions with properties similar to that of the amphibian organizer. This points to the possibility of a close molecular similarity between the Xenopus and Hydra organizers. The constitutive expression of a noggin-like gene in Hydra may be responsible for its regenerative capacity.
Assuntos
Animais , Proteínas de Transporte , Clonagem Molecular , Proteína Goosecoid , Proteínas de Homeodomínio/genética , Hydra/anatomia & histologia , Hibridização In Situ , Organizadores Embrionários , Proteínas/genética , Proteínas Repressoras , Fatores de Transcrição , Xenopus laevis/genéticaRESUMO
Most important event in head regeneration in hydra is a wave of conversion of many interstitial cells into nerve cells. Experimental evidence lends support to the idea that the commitment of interstitial cells into nerve cells is the first morphogenetic prerequisite for emergence of head structures, when the number of nerve cells increases. This increase in nerve cells is delayed when regeneration occurs at a site lower in the body column.