Polarity in the rabbit embryo.
The main aim of the gastrulation process is commonly regarded to be the generation of the definitive germ layers known as mesoderm, endoderm and ectoderm. Here we discuss how the topography of gene expression, cellular migration and proliferative activity in the preliminary germ layers (hypoblast and epiblast) of the rabbit embryo reveal the sequence of events that establishes the three major body axes. We present a testable model in which a combination of cellular movement in the hypoblast with a morphogen gradient created by the (extraembryonic) trophoblast creates morphological polarity in the embryo and, hence, the co-ordinates for germ layer formation.
Idkowiak
Jan
J
Department of Anatomy and Cell Biology, Martin-Luther University, Grosse Steinstrasse 56, 06097 Halle, Germany.
Weisheit
Gunnar
G
Viebahn
Christoph
C
D000818:Animals; D019521:Body Patterning / Q000502:physiology*; D002465:Cell Movement / Q000502:physiology; D004622:Embryo, Mammalian / Q000502:physiology*; D005775:Gastrula / Q000502:physiology; D015870:Gene Expression / Q000502:physiology; D011817:Rabbits