As a complementary view of Figure 1, genes were coloured at each time, according to their log2(Ratio) values using the common coloured code (green for negative values and red for positive ones). The resulting figures give rough snapshots of the expression levels of all the genes at a given time during the course. At the begining (time 0h), all the genes show a basal expression. But after 2h, we can observe, for both species, a gradual coloration between up-regulated genes located on the right side of the 3D representation and genes located in the highly connected regions, which are still not significantly expressed. After 5h and 11h, that is genes located in the highly connected region which are the most up-regulated.

Figure legend : (A) The 724 and 518 genes significantly induced during the sporulation process in the fission (green color) and budding (blue color) yeasts were mapped in a 3-dimensional space, according to the expression measurements during the time course experiments described in Mata et al. 2002 and Chu et al. 1998. Points represent genes, and white segments link pairs of genes whose the inter-gene distance between their expression measurements is less than a threshold Do = 0.3 (a conventional correlation higher than 0.95). 3D visualizations and snapshots were performed using the rgl package.
(B) Genes were coloured according to their log2(Ratio) values at different times (0h, 2h, 5h and 11h). Genes with log2(Ratio) of 0 (expression unchanged) are represented in black, increases in expression relative to reference cells are represented in graded shades of red, and descreases as graded shades of green. Unlike in (A), only the first and the second coordinates are shown here.