Coevolution between snoRNAs and their targets. A. Nucleotides of box C/D snoRNAs in the complementary region were changed in coordination with its target rRNA maintaining phylogenetical conservation of rRNA methylated sites. B. Nucleotides changed in box H/ACA snoRNAs respond to specific changes in the 18S rRNA of N. crassa . The nucleotides marked by black dot represent the 2'-O-methylation. Basepairs changed are indicated by arrows.
Liu et al. BMC Genomics 2009 10:515 doi:10.1186/1471-2164-10-515