Merozoite gene expression supports published data and forms a distinct grouping when compared with other life cycle stages. (A) Heat map of expression (left, this study) and binary indication of labeling by IHC (right) for genes that were assessed for merozoite stage expression previously . There was excellent agreement when the two studies are compared, where, for example, gene products that did not label by IHC at the merozoite stage (-) were not expressed as indicated by the microarray data (blue). (B) Principal component analysis (PCA) highlighted the unique profile of the merozoite samples placing them approximately half-way on a continuum between the tachyzoite/bradyzoite and oocyst samples. The first two components described a combined 75% of the variance across the samples.