The taxonomic distribution of existing snoRNA annotations. The figure displays a tree derived from the top three levels of the National Center for Biotechnology Information (NCBI) taxonomy. Mapped onto this are counts of: (1) the snoRNP-associated Pfam 24.0 domains Nop, Nop10p, Gar1, SHQ1, fibrillarin and TruB_N (blue); (2) the small subunit (SSU) rRNA regions annotated by Rfam 10.0 (green); (3) genome projects registered as completed, draft or in progress from the GOLD database (version 3.0, October 22, 2009) (gold); (4) all snoRNA regions annotated by Rfam 10.0 (red); (5) EMBL sequences annotated as snoRNAs that are also annotated by Rfam 10.0 (pink). We only show here the lineages where a significant amount of sequencing effort has been directed (see Supplementary Table 1 in Additional data file 1 for the full results). Lengths of the bars correspond to counts in each taxa for each category. The shortest bar length corresponds to counts between 1 and 10 (exclusive), the next shortest is between 10 and 100 (exclusive), and so on.