Figure 1.

G₂ arrest mediated by Mos requires Xe-Wee1. (A) CSF extracts were prepared and supplemented with wild-type MBP-Mos (top). Xe-Wee1 was depleted from the CSF extract or the extract was mock depleted with preimmune sera (bottom). (B) The cell cycle was initiated by the addition of calcium, samples were taken at 10-min intervals and assayed for histone H1 kinase activity. Note that the endogenous Mos does not degrade efficiently in these extracts as compared to intact eggs (see Fig. 6B,F; Watanabe et al. 1991).