Titel: The evolution of dorsoventral patterning in insects
Startdatum: 04 Mai
Startzeit: 17:00
Stoppzeit: 18:30Uhr
Prof. Dr. Siegfried Roth 
Ort: Seminarraum 3139

Toll-dependent patterning of the dorsoventral axis in Drosophila represents one of the best-understood gene regulatory networks. However, its evolutionary origin has remained elusive. Outside the insects Toll is not known for a patterning function, but rather for a role in pathogen defense. I will present our recent findings on the evolution of dorsoventral patterning in insects. In particular, I will describe our work on a hemimetabolous insect, the milkweed bug Oncopeltus fasciatus, whose lineage split from Drosophila’s more than 350 million years ago. In Oncopeltus, Toll is only required to polarize a dynamic BMP signaling network. Modeling of this network reveals that shallow Toll signaling gradients are sufficient to initiate axis formation. Dynamic BMP signaling combined with long-range, shallow Toll signaling gradients can explain the twinning of embryos upon egg fragmentation, which has been observed in many insect lineages.