Figure 3.

Injection of Cdc25 mRNA after establishment of late replication can shorten S-phase 14. (A) Time courses for 50 individual His2AvD-GFP embryos (each represented as a separate position on the Y-axis) that were induced into an extra mitosis (red circles) by injection of Stg mRNA (blue triangles) or Twe mRNA (yellow triangles). Other experimental embryos (18) that did not undergo an induced mitosis are omitted from the graph, but are tabulated in B. A live record of each embryo spanned the time course except for a brief interruption around the time of injection. Time (X-axis) is recorded in relation to the end of mitosis 13 (thick vertical line). A black bracket highlights embryos injected during S-phase 14 with shortened S phases. (B) Tabulation of interphase times. Treatments are grouped in several ways to illustrate their relative efficacy. For Cdc25 in cycle 14, the time between injection and entry into mitosis is also given (**). “Affected fraction” is affected/total injected, and “I14 length” is in hours:minutes:seconds ± the standard deviation and is calculated from only the affected embryos.