Asynchronous Cell Division in Medaka before MBT Figure 4. Cell volumes at the 4-cell stage. Variability of cell volumes at the 4-cell stage. (A) Maximum intensity z-projections of confocal stacks of medaka embryos at the 1-cell, 2-cell and 4-cell stage. Diffuse cellular boundaries during the 1-cell and 2-cell stages cannot be detected by software protocols. Cell membranes at the 4-cell stage are sharp and clearly separated between single cells and yolk. (B) Volumes from cells of different embryos. Graph displays the divergence of cellular volumes within individual embryos at 4-cell stage. X-axis shows individual embryos with increasing cell-volume differences to the right. (C) Relative factor differences between the largest and the smallest cell of individual embryos. (B and C) Background colors within the graphs indicate the embryo-type: type I embryos are represented by green, type II embryos by blue and type III embryos are represented by orange. doi:10.1371/journal.pone.0021741.g004 PLoS ONE | www.plosone.org 7 July 2011 | Volume 6 | Issue 7 | e21741