Abstract
We have recently found that Blimp-1, which induced directly by ecdysone plays important roles in determining the precise timing of FTZ-F1 expression and the timing of pupation by working as a transcriptional repressor in D. melanogaster. Analysis of regulation mechanism of Blimp-1 expression reveals that the blimp-1 gene products are only present at high ecdysone titer period because of their instability. We also obtained results to show that proline rich region of Blimp-1 carry a degradation signal for rapid turnover and this signal plays an important role to determine the timing of pupation. To evaluate the region more, we are planning to analyze related Drosophila species, which show different pupation timing.