Chromosome landscape of mRNA expression in Toxoplasma. SAGE tag distribution with respect to three classes of co-regulated mRNAs are indicated in each chromosome assembly ; sporozoite- (red), Day-7 (blue) and Day-15/pH-shift (green) specific. Transcriptional orientation for each tag plotted is indicated by the up (forward) or down (reverse) direction of the corresponding mark. Inset Venn diagram shows the overall number of unique tags represented and demonstrates that there is no overlap in the expression of these classes of mRNA. The expanded diagram demonstrates the differentiation expression of the tandem head-to-tail sequences encoding enolase 1 and 2.