Figure 2

Cluster analysis of microarray data. (A) Hierarchical clustering was used to group the up-regulated genes (false discovery rate < 5%) based on similar expression patterns over the five developmental intervals examined (S2-3, S5, S6-7, S8-9 and S10-12 embryos, indicated above the columns). Gene expression patterns are evident across the rows. Increased and decreased expression compared with the mean expression of the S6-7 sample for each gene is shown in red and green, respectively. Green indicates log₂ ratios < 0, and red indicates values >0. Three main gene groups were resolved and indicated by color bars shown to the right of the figure. (B) Graphs indicate genes that displayed a similar time-dependent expression pattern. y axis: log₂ of expression ratio between each developmental interval and S6-7; x axis: developmental intervals.