Cleavage patterns and gastrulation as complex characters for phylogenetic inferences in the Metazoa: the early development of Phoronida and Rotifera and its relation to spiral cleavage


The analysis of early ontogenetic stages can contribute to the question whether the tentaculate groups (Phoronida, Brachiopoda, Bryozoa) are more closely related to the Deuterostomia (Radialia hypothesis) or the Spiralia (Lophotrochozoa hypothesis). A similar problem occurs with the Rotifera which, together with the Acanthocephala, are either seen as nemathelminth representatives or as more closely related to various spiralian or lophotrochozoan taxa. The Lophotrochozoa hypothesis implies a relationship of tentaculate and rotifer cleavage modes to the spiral cleavage. Our knowledge about the cleavage pattern and the gastrulation of tentaculates and rotifers 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 Phoronida as representatives of tentaculates and Rotifera in great detail with a variety of methods ranging from histology to 4D-microscopy. It will be tested whether phoronids and rotifers show spiral cleavage or traces thereof. Therefore, the results are compared to the published data on spiral cleavage. Furthermore, to test alternative hypothesis of relationships the patterns resulting from our study will be compared with the published data on developmental patterns.


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

Financer
DFG: Sachbeihilfe

Duration of project
Start date: 12/2007
End date: 05/2011

Last updated on 2022-07-09 at 21:09