First published online January 14, 2005
Development 132, 302e (2005)
© The Company of Biologists Limited
Early embryonic inequalities
The cells in early mouse embryos are generally thought to have equivalent
developmental properties until at least the eight-cell stage. On
p. 479,
Piotrowska-Nitsche and colleagues challenge this idea by showing for the first
time that four-cell stage mouse blastomeres have different developmental
properties that depend on their embryonic origin. In most two-cell mouse
embryos, one cell divides meridionally and the other divides equatorially or
obliquely with respect to the second polar body. The researchers report that
chimaeras made entirely of specific equatorially or obliquely derived
four-cell stage blastomeres show developmental abnormalities - those made from
the most vegetal blastomeres are most severely affected. By contrast,
chimaeras made from meridionally derived blastomeres develop normally.
However, when individual blastomeres are surrounded by blastomeres from random
positions, they contribute to all embryonic lineages. Thus, although four-cell
stage blastomeres all have full developmental potential, they differ in their
developmental properties.
Related articles in Development:
- Four-cell stage mouse blastomeres have different developmental properties
- Karolina Piotrowska-Nitsche, Aitana Perea-Gomez, Seiki Haraguchi, and Magdalena Zernicka-Goetz
Development 2005 132: 479-490.
[Abstract]
[Full Text]
