Roux's archives of developmental biology

, Volume 200, Issue 3, pp 143–148

Prospective fate of early blastomeres in Hydractinia echinata (Cnidaria, Hydrozoa)

  • Axel Schlawny
  • Hans-Dieter Pfannenstiel
Original Articles

DOI: 10.1007/BF00190233

Cite this article as:
Schlawny, A. & Pfannenstiel, H. Roux's Arch Dev Biol (1991) 200: 143. doi:10.1007/BF00190233

Summary

Blastomeres of two-cell, four-cell, and eight-cell embryos of Hydractinia echinata were injected with horseradish-peroxidase (HRP) or fluorescein isothiocyanate (FITC)-dextran. The fate of the descendants of the injected blastomeres was followed until the planula larva had developed. The results obtained after HRP or FITC-dextran injection were essentially the same. Blastomeres are equivalent up to the four-cell stage, i.e. half-blastomeres produce half of the ectoderm of the planula larva and quarter-blastomeres give rise to one quarter of the larval ectoderm. During normal embryogenesis, the larval anterior-posterior axis corresponds to the animal-vegetal axis of the zygote. Thus, the labelled areas of larvae consisting of the progeny of injected half or quarter blastomeres normally stretch along the larval anterior-posterior axis. Normally, material giving rise to anterior or posterior larval parts, respectively, is separated at the third cleavage. Irrespective of the type of experiment, the progeny of injected blastomeres always contributed to endoderm formation, i.e. in larvae resulting from injected embryos the endoderm was more or less uniformly labelled. Application of vital stains locally to the exterior of zygotes and following these markers through first and second cleavage, produced evidence that in the vast majority of cases, the second cleavage is meridional.

Key words

Cell lineageHRPFITC-dextranCleavageAxis determinationHydroids

Copyright information

© Springer-Verlag 1991

Authors and Affiliations

  • Axel Schlawny
    • 1
  • Hans-Dieter Pfannenstiel
    • 1
  1. 1.Institut für Zoologie der Freien Universität BerlinBerlinFederal Republic of Germany