Fig. 7.

Hierarchical clustering of piRNA expression. Normalized expression profiles of 303 piRNAs from six developmental stages were clustered. The stages are in columns, and the piRNAs are in rows. Red indicates that a gene is strongly represented at the stage, black indicates the intermediate expression whereas green indicates low expression. The colour scale bar shown at the bottom of the figure indicates the log₂ value of fold change. piRNAs with similar expression patterns cluster together. There are nine clusters with variable numbers of sub-clusters. Abbreviations: E, embryos; L, larvae; P, pupae; M, adult males; F, adult females; B, blood-fed adult females