Seminars and Events

Past Events

Category Other
Date and Time 2017-03-08 15:00 - 17:00
Venue Seminar Room A7F
Speaker Yuji Yamazaki
Affiliation Lewis-Sigler Institute, Princeton University
Title Enhancers mediating temporal dynamics in the Drosophila embryo
Poster click here to download(PDF)
Host Tatsuo Shibata
Summary Gastrulation of the Drosophila embryo is a premier model system for tissue morphogenesis. Particular efforts have focused on the formation of the ventral furrow, whereby ~1,000 presumptive mesoderm cells exhibit coordinated apical constrictions that mediate invagination. Apical constriction depends on a Rho GTPase signaling pathway (Fog/T48) deployed by the developmental regulatory genes twist and snail. The consensus states that coordinate mesoderm constriction depends on high levels of myosin along the ventral midline, although the basis for this myosin localization activity is uncertain. Using the newly developed quantitative live imaging methods, we showed that two key cellular effectors of the Rho signaling pathway, T48 and Fog, exhibit dynamic temporal changes in de novo transcription. Their transcription begins as a narrow strip of 2-3 cells along the ventral midline and coherently expanding into more ventral-lateral regions. Quantitative image analyses suggest these temporal gradients produce graded levels of t48 and fog expression along the DV axis. These are likely to contribute to the graded distribution of myosin accumulation in the mesoderm prior to the onset of ventral furrow formation. We therefore propose that transcriptional temporal pre-patterning is an intrinsic mechanism for robust morphogenesis.