Figure 1.

Correlation inconsistency in the expression of some gene pairs between different experiments. For each gene pair, CCF values obtained from combining expression profiles of all experiments (CCF_TOTAL, x-axis) are plotted versus those of individual experiments (CCF_EXPERIMENT, y-axis). Only gene pairs with a CCF_TOTAL value above 0.5 or below -0.5 are shown. x- and y-axis values go from -1 to 1 in steps of 0.5 as depicted in (a). (b-d) Genes involved in the cell cycle: (b) alpha-factor, (c) elutriation and (d) cdc-15 strain. (e) Sporulation. (f, g) Response to stress: (f) heat and (g) cold shocks. (h) Diauxic shift. CCF_EXPERIMENT values can spread over a considerable range regardless of their CCF_TOTAL (for example, heat shock), even to the point of being significant and with opposite sign to CCF_TOTAL (for example, cold stress and diauxic shift). This inconsistency is less pronounced in the sporulation data, perhaps because it contains very high intensity values that may bias the CCF_TOTAL to be more similar to CCF_spo. Note that only genes whose expression was increased or decreased by 2.3-fold were considered. Those that did not pass the filtering were given a value equal to zero.