Fig. S6.

The hb and Kr expression domain borders undergo dynamic shifts within 17 h to 20 h AEL in Tribolium blastoderm. To examine if the shifting of hb and Kr expression domain borders is smooth, we analyzed their dynamics with higher temporal resolution. The last cycle of synchronous mitoses in the Tribolium blastoderm stops before 14 h AEL (5). Midway during the 17- to 20-h window, the blastoderm starts a phase of asynchronous mitoses that lasts until 23 h AEL. We compared border positions of hb and Kr expression domains in early versus later times within the 17- to 20-h window, marked by the lack and possession of mitoses, respectively. We found that the anterior borders of both hb and Kr indeed shift smoothly from posterior to anterior. (A) Positions of anterior and posterior borders of hb expression domain along the AP axis of Tribolium blastoderm during the no mitosis phase (early within 17 h to 20 h AEL) and the mitosis phase (late within 17 h to 20 h AEL). (B) Position of anterior border of Kr expression domain along the AP axis of Tribolium blastoderm during the no mitosis phase and the mitosis phase.