Cleavage patterns and gastrulation as complex characters for phylogenetic inferences in the Metazoa: a contribution to the Articulata/Ecdysozoa controversy


The question of the phylogenetic position of the Arthropoda is a central issue for our understanding of Metazoan phylogeny. The analysis of early ontogenetic stages can contribute to the solution of the question whether the Arthropoda are more closely related to the Annelida (Articulata hypothesis) or the Nemathelminthes (Ecdysozoa hypothesis). The Articulata hypothesis implies a derivation of the arthropod cleavage from the spiral cleavage mode. Our knowledge about the cleavage pattern and the gastrulation of many arthropods is still fragmentary. To fill these gaps we want to study the early cleavage patterns, the cell lineages, the cell fates, and the gastrulation modes of representatives of the Pantopoda (Chelicerata) and the Cirripedia (Crustacea) in great detail with a variety of methods ranging from histology to 4-D microscopy. With the data at hand we will try to reconstruct the ground pattern of the cleavage of the Euarthropoda. It will be tested whether arthropods show spiral cleavage or traces thereof. Therefore, the results are compared to the published data on spiral cleavage. Furthermore, to test the Ecdysozoa hypothesis the patterns resulting from our study will be compared with the published data on comparable developmental patterns in Nematoda Gastrotricha, Priapulida, and Nematomorpha.


Principal investigators
Scholtz, Gerhard Prof. Dr. rer. nat. (Details) (Comparative Zoology)

Financer
DFG: Sachbeihilfe

Duration of project
Start date: 01/2006
End date: 12/2008

Last updated on 2022-07-09 at 23:09