<i>polished rice</i> mediates ecdysone?dependent control of <i>Drosophila</i> embryonic organogenesis

In many animals, progression of developmental stages is temporally controlled by steroid hormones. Drosophila, the level ecdysone titer oscillates and stage transitions, such as larval molting metamorphosis, are induced at each peaks. Ecdysone also peaks mid-embryogenesis embryonic necessary for morphogenesis several organs, although regulatory mechanisms organogenesis dependent on signaling still open questions. this study, we find that absence or interruption caused multiple defects in tracheal system, including decrease luminal protein deposition, uneven dilation dorsal trunk loss terminal branches. We reveal an ecdysone-inducible gene polished rice (pri) essential tip cell fate decision As over-expression pri can restore disturbance biosynthesis, functions one major mediators signal tracheogenesis. These results demonstrate its downstream target play roles development modulating decision.