Unité de Biologie du Développement
(UMR7009), CNRS/UPMC,
Station Zoologique, Observatoire Océanologique,
06230 Villefranche-sur-mer, France
Website: http://biodev.obs-vlfr.fr/recherche/yas/
Chordate embryos share a similar fate map at the equivalent of the
blastula stage and by larval stages exhibit a distinct body plan,
organised with a central notochord, dorsal neural tube and ventral
endoderm. We are studying embryogenesis of the ascidian, Ciona
intestinalis, as a simple model to address how the chordate body plan
is established. One of the advantages of ascidian embryogenesis is that
it proceeds with a small number of cells (for instance, gastrulation
starts when the embryo consists of 110 cells). In addition, cell
lineages are fully documented until the onset of gastrulation and
further for some tissue types. These features allow us to ask
embryological questions at the level of individual cells. We will
present our recent results on two embryonic events that we have been
focusing on, which are 1) how axial mesoderm and neural tissues are
specified from common lineages and 2) how these neural cells becomes
subsequently patterned within the neural plate.
PART
1)
ASYMMETRIC CELL DIVISIONS ARE ASSOCIATED WITH THE CELL FATE CHOICE
BETWEEN MESODERMAL AND NEURAL TISSUES IN THE ASCIDIAN, CIONA
INTESTINALIS.
Hitoyoshi Yasuo, Vincent Picco and Clare Hudson
PART
2)
NODAL SIGNALLING IS REQUIRED FOR PATTERNING ACROSS THE MEDIAL-LATERAL
AXIS OF THE ASCIDIAN NEURAL PLATE. Clare
Hudson and Hitoyoshi Yasuo