Analysis of morphogenetic mutants of hydra
- 15 Downloads
Non-budding mutants ofChlorohydra viridissima regenerate heads 6 h faster thanHydra attenuata and the number of tentacles per head is higher. The polarity in pieces from the gastric region is the more labile, the smaller the pieces are. In regenerates heads and tentacles form much more frequently than feet, giving rise to bipolar or multiheaded structures. Buds very seldom form under normal conditions, but they occasionally occur in regenerating animals with two cut surfaces.
The higher head-forming potential in the mutant is paralleled by a higher head-activator concentration (20-fold in head, 4-fold in body), than inHydra attenuata, which is not accompanied by an equivalent increase in head-inhibitor concentration (1.4-fold in head, 2-fold in body). The foot-activator concentration is slightly reduced (1.3-fold), the foot-inhibitor concentration is higher (1.6-fold) than inH. attenuata. The mutant is extremely insensitive to head activator, relatively insensitive to head inhibitor and foot inhibitor, but sensitive to foot activator.
Key wordsHydra mutant Morphogenetic substances Bud formation
Unable to display preview. Download preview PDF.
- Berking, S.: Bud formation inHydra: Inhibition by an endogenous morphogen. Wilhelm Roux's Archives181, 215–225 (1977)Google Scholar
- Lenhoff, H.: Cellular segregation and heterocytic dominance in hydra. Science148, 1105–1107 (1965)Google Scholar
- Lenhoff, H., Rutherford, C., Heath, H.: Anomalies of growth and form in hydra. Polarity, gradients, and a neoplasia analog. Nat. Cancer Inst. Monogr.31, 709–737 (1969)Google Scholar
- Moore, L. B., Campbell, R. D.: Non-budding strains of hydra: Isolation from sexual crosses and developmental regulation of form. J. Exp. Zool.185, 73–81 (1973)Google Scholar
- Schaller, H. C., Schmidt, T., Flick, K., Grimmelikhuijzen, C. J. P.: Analysis of morphogenetic mutants ofHydra. I. TheAberrant. Wilhelm Roux's Archives183, 193–206 (1977)Google Scholar