 R9 is a member of the C/D box class of snoRNAs which contain the conserved sequence motifs known as the C box (UGAUGA) and the D box (CUGA).Most of the members of the box C/D family function in directing site-specific 2'-O-methylation of substrate RNAs.This plant snoRNA was identified in "Arabidopsis thaliana" by computational screening and experimentally verified by primer extension analysis.