Fig. 8.

Model for the requirement of mypt1 in the regulation of myosin during zebrafish brain morphogenesis. Mypt1 is required for proper rhombomeric cell shape at 19 hpf. It is also required later for progression of rhombomere morphology and for brain ventricle expansion. The requirement for Mypt1 during the development of rhombomere morphology and during ventricle opening is unclear. However, our data suggest that myosin might be required for these earlier steps, which would in turn indicate that Mypt1 inhibition of myosin phosphatase might be required during these processes.