First published online March 4, 2005
Development 132, 602e (2005)
© The Company of Biologists Limited
Tardigrade development dissected
Tardigrades are poorly studied aquatic arthropods. Now a 3D time-lapse
recording of the development of the tardigrade Thulinia stephaniae
from embryogenesis to hatching provides new information on the ancestral mode
of early development in Arthropoda (see
p. 1349). By tracking
the fate of individual cells in living embryos, Hejnol and Schnabel reveal
that T. stephaniae embryos undergo an irregular indeterminate
cleavage pattern. Furthermore, early embryogenesis is highly regulative; even
after laser ablation of half the embryo at the two- or four-cell stage, normal
juveniles develop, a degree of recovery from blastomere ablation not
previously seen in protostome embryos. Because tardigrades are a basal lineage
within the Arthropoda, a comparison of these new details of tardigrade
development with those of other protostomes, such as crustaceans, suggests
that indeterminate cleavage and regulatory development are part of the ground
pattern of Arthropoda and probably all
Ecdysozoa.
Related articles in Development:
- The eutardigrade Thulinia stephaniae has an indeterminate development and the potential to regulate early blastomere ablations
- Andreas Hejnol and Ralf Schnabel
Development 2005 132: 1349-1361.
[Abstract]
[Full Text]