Figure 2

Clustering and gene ontology (GO) annotation of the cycling genes in summer. The 556 cycling genes in summer were classified into four clusters (clusters 1 to 4) by their expression patterns in microarray data (A), and categorized by GO annotation into the major functional categories of cellular component (B), molecular function (C) and biological process (D). Each cluster corresponds to a gene group derived from (A). Gray and black bars below graph (A) respectively represent natural length of day and night (measured between sunrise and sunset) reported by the National Astronomical Observatory of Japan. `all’ indicates all genes on the microarray and `cycling’ indicates all 556 cycling genes.