The first cleavage plane and the embryonic axis are determined by separate mechanisms in Xenopus laevis. I. Independence in undisturbed embryos

Michael Danilchik, Steven D. Black

Research output: Contribution to journalArticle

36 Scopus citations


We examined the spatial relationships between the meridian of sperm entry the plane of first cleavage, and the embryonic axis (defined by the neural groove) in eggs of Xenopus laevis. Direct measurement of the angular separations between these embryonic structures in gelatin-embedded eggs confirmed the classical conclusion that the sperm entry point and neural groove tend to form on opposite sides of the egg, and also revealed that the first cleavage plane has a nearly random orientation with respect to the neural groove. We next examined the distortion of the first cleavage plane that results from the normal processes of convergence and extension during gastrulation and neurulation. We permanently marked the first cleavage plane by injecting one blastomere of the two-cell embryo with a fluorescent lineage marker. At the start of gastrulation, the interface between the labeled and unlabeled regions was almost randomly oriented relative to the dorsal blastopore lip, confirming our first set of observations. In embryos with the interface

Original languageEnglish (US)
Pages (from-to)58-64
Number of pages7
JournalDevelopmental Biology
Issue number1
Publication statusPublished - 1988
Externally publishedYes


ASJC Scopus subject areas

  • Developmental Biology

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