Publisher Correction: A cdk1 gradient guides surface contraction waves in oocytes.

A Supplementary Information file from a different paper was inadvertently published with the original version of this Article. This file was replaced with the correct Supplementary Information file on 24 October 2017.

A cdk1 gradient guides surface contraction waves in oocytes.

Surface contraction waves (SCWs) in oocytes and embryos lead to large-scale shape changes coupled to cell cycle transitions and are spatially coordinated with the cell axis. Here, we show that SCWs in the starfish oocyte are generated by a traveling band of myosin II-driven cortical contractility. At the front of the band, contractility is activated by removal of cdk1 inhibition of the RhoA/RhoA kinase/myosin II signaling module, while at the rear, contractility is switched off by negative feedback originating downstream of RhoA kinase.

Identification of optimal parameter combinations for the emergence of bistability.

Bistability underlies cellular memory and maintains alternative differentiation states. Bistability can emerge only if its parameter range is either physically realizable or can be enlarged to become realizable. We derived a general rule and showed that the bistable range of a reaction parameter is maximized by a pair of other parameters in any gene regulatory network provided they satisfy a general condition.