Eye lens development and gamma crystallins in Discoglossus pictus (Anura).

The ontogeny and localization of the gamma crystallins in Discoglossus pictus lens development has been determined. Using antibody specific for amphibian gamma crystallins in the immunofluorescence technique, it was found that gamma crystallins first appear in primary lens fibre cells in the lens rudiment, and continue to be restricted to the fibre area as lens development progresses. Thus the role of gamma crystallins as indicators of a differentiated state remains constant in amphibian evolution, having been demonstrated in the most archaic anuran superfamily, as well as in others more recently evolved.     

Preparation of specific antiserum against Rana esculenta pre-alpha lens crystallin.

Specific antiserum against Rana esculenta lens pre-alpha crystallin was prepared in a rabbit by injecting antigen-antibody precipitate of this crystallin obtained from immunoelectrophoresis of esculenta total soluble lens proteins against homologous antiserum.     

Preparation of specific antisera against chicken lens protein components

Zusammenfassung Kaninchen wurden gegenüber Eiweissfraktionen, aus denen chromatographisch ein bestimmtes Protein entfernt war, tolerant gemacht. Durch Injektion eines ungereinigten Präparats des eliminierten Proteins während der toleranten Phase war es aber trotzdem möglich, einen für dieses Protein spezifischen Antikörper hervorzurufen.     

Studies on lens regeneration inXenopus laevis

Zusammenfassung Es wurde die Regeneration der Augenlinse erwachsenerXenopus laevis nachuntersucht. Eine vollständige Entfernung der Linse gelang in wenigen Fällen. Die Neuentwicklung der Linse wurde nur von Linsenepithelresten, die nach der Lentektomie in der Kapsel zurückgeblieben waren, induziert.     

Preparation of specific antiserum againstRana esculenta pre-α lens crystallin

Summary Specific antiserum againstRana esculenta lens pre- crystallin was prepared in a rabbit by injecting antigen-antibody precipitate of this crystallin obtained from immunoelectrophoresis ofesculenta total soluble lens proteins against homologous antiserum.Acknowledgments. We thank Mr.A. Wachter for the excellent technical help, Mr.Th. Hulskes and Mr.A. M. v. Egeraat for the illustrations and finally Dr.W. E. Hawkins for valuable discussion.     

Determination of the influence of size in the differentiation of an isolate

Résumé On a détaché de l'ectoderme présomptif neural de migastrulae deTriturus alpestris des lambeaux de grandeur définie qui ont été sectionnés au hasard en fragments d'une demi, d'un quart et d'un sixième, puis emballés dans de l'ectoderme deXenopus ouTriturus et mises en culture dans la solution d'Holtfreter. Il a été constaté que le % des cas où une différenciation neurale s'est produite décroît avec la taille du fragment.     

An autoradiographic study of the uptake of3H-leucine during primary embryonic induction in vitro

Zusammenfassung Mit Hilfe von radioaktiv markiertem Leucin wird gezeigt, dass das Mesoderm seine Induktionswirkung auf das Ectoderm ausübt, bevor histogenetische Differenzierung einsetzt.

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This research was supported by the U.S. Atomic Energy Commission under contract with the Union Carbide Corporation.S. K. Brahma was a Damon Runyon Memorial Fund fellow.     

Eye lens development and γ crystallins in Discoglossus pictus (Anura)

Summary The ontogeny and localization of the crystallins in Discoglossus pictus lens development has been determined. Using antibody specific for amphibian crystallins in the immunofluorescence technique, it was found that crystallins first appear in primary lens fibre cells in the lens rudiment, and continue to be restricted to the fibre area as lens development progresses. Thus the role of crystallins as indicators of a differentiated state remains constant in amphibian evolution, having been demonstrated in the most archaic anuran superfamily, as well as in others more recently evolved.This research was largely accomplished during the tenure of a fellowship from the European Molecular Biology Organization to D. S. McDevitt, and was partially supported by Biomedical Research Support Grant RR 546414 to D. S. McDevitt.The authors are grateful to Prof. W. J. van Doorenmaalen for use of the laboratory facilities; and to the Hubrecht Laboratory, International Embryological Institute, Utrecht, The Netherlands, for the gift of live D. pictus eggs. We thank Miss C. M. J. Stuifsand for the normal histology and Mr Th. Hulskes for the illustrations.