Summary
The effect of aging on the neural competence of the presumptive ectoderm of the early gastrula, and the effect of aged ectoderm on the differentiation of the still uninvaginated dorsal blastoporal lip at the small yolk-plug stage — representing the trunk organizer — were examined by the sandwich method inCynops pyrrhogaster.
The presumptive ectoderm to be used as reaction system was taken from 0 to 36 h exogastrulae obtained by operation at the early gastrula stage and combined with trunk organizer. In the 0 to 12 h explants typical trunktail structures were formed. With further aging of the presumptive ectoderm a decrease in frequency of spinal cord, notochord, and muscle and a simultaneous increase in frequency of mesenchyme and mesothelium were observed. In the 30 and 36 h explants neural competence had largely disappeared, the frequency of notochord and muscle become very low and their differentiation very poor, whereas the frequency of mesenchyme and mesothelium reached very high levels.
We infer a reciprocal relationship between the induced spinal cord and the differentiation of notochord and muscle, as well as a transformation of notochordal material into mesenchyme and mesothelium under the influence of the aged ectoderm. The mode of action of the trunk organizer in normal development is discussed.
Similar content being viewed by others
References
Gallera, J.: Inductíons céphaliques dans l'ectoblaste vieillissant (Triturus alpestris). Wilhelm Roux' Archiv.146, 21–67 (1952)
Gebhardt, D.O.E., Nieuwkoop, P.D.: The influence of lithium on the competence of the ectoderm inAmbystoma mexicanum. J. Embryol. Exp. Morpol.12, 317–331 (1964)
Holtfreter, J.: Die totale Exogastrulation, eine Selbstablösung des Ektoderms von Entomesoderm. Entwicklung und funktionelles Verhalten nervenloser Organe. Wilhelm Roux' Archiv.129, 669–693 (1933)
Holtfreter, J.: Veränderungen der Reaktionsweise im alternden isolierten Gastrulaektoderm. Wilhelm Roux' Archiv.138, 163–196 (1938)
Kato, K.I.: Studies on the differentiating potencies of the dorsal part of the blastoporal lip inTriturus-gastrula. III. Quantity of material in the notochordal differentiation. Mem. Coll. Sci. Univ. Kyoto (B)30, 21–28 (1963a)
Kato, K.I.: Neuro-notochordal relationship in the development of the explanted pieces taken from the dorsal lip ofTriturus-gastrulae. Mem. Coll. Sci. Univ. Kyoto (B)30, 29–39 (1963b)
Kato, K.I., Okada, T.S.: A mutual relationship between the explanted piece of dorsal blastoporal lip and the enveloping ectoderm inTriturus-gastrula. Mem. Coll. Sci. Univ. Kyoto (B)23, 1–9 (1956)
Leikola, A.: The mesodermal and neural competence of isolated gastrula ectoderm studied by heterogeneous inductors. Ann. Zool. Soc. ‘Vanamo’25, 1–49 (1963)
Leikola, A.: On the loss of mesodermal competence of theTriturus gastrula ectoderm in vivo. Experientia21, 458–459 (1965)
Muchmore, W.B.: The influence of embryonic neural tissues on differentiation of striated muscle inAmbystoma. J. Exp. Zool.139, 181–188 (1958)
Okada, Yô K. Hama, T.: Examination of regional differences in the inductive activity of the organizer by means of transplantation into ectodermal vesicles. Proc. Imp. Acad. (Tokyo)19, 48–53 (1943)
Okada, Yô K., Ichikawa, M.: Normal table ofTriturus pyrrhogaster (revised). Jpn. J. Exp. Morph.3, 1–6 (1947)
Okada, Yô K., Takaya, H.: Experimental investigation of regional differences in the inductive capacity of the organizer. Proc. Imp. Acad. (Tokyo)18, 505–513 (1942a)
Okada, Yô K., Takaya, H.: Further studies upon the regional differentiation of the inductive capacity of the organizer. Proc. Jmp. Acad. (Tokyo)18, 514–519 (1942b)
Pertusa, J.: A simple technique for the preservation of vital dyes in fixed and sectined embryos. J. Embryol. Exp. Morphol.15, 131–132 (1966)
Sasaki, N., Iyeiri, S., Tadokoro, T.: Disappearance of primary competence of the gastrula ectoderm inTriturus pyrrhogaster embryo (in Japanese with English abstract) Zool. Mag. (Tokyo)84, 148–150 (1975)
Saxén, L., Toivonen, S.: Primary embryonic induction. London: Logos Press 1962
Spemann, H.: Über den Anteil von Implantat und Wirtskeim an der Orientierung und Beschaffenheit der induzierten Embryonalanlage. Wilhelm Roux' Archiv.123, 389–517 (1931)
Tada, H.: The localization of pigment cell-producing areas in the newt neurula (in Japanese with English abstract). Zool. Mag. (Tokyo)56, 25–28 (1944a)
Tada, H.: Disappearance of the pigment cell-forming potency of neural plate ofTriturus pyrrhogaster (in Japanese). Zool. Mag. (Tokyo)56, 29–31 (1944b)
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Ohara, A., Hama, T. The effect of aging on the neural competence of the presumptive ectoderm and the effect of aged ectoderm on the differentiation of the trunk organizer inCynops pyrrhogaster . Wilhelm Roux' Archiv 187, 13–23 (1979). https://doi.org/10.1007/BF00848163
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00848163