Figure 2
Sequence divergence of miRNA loci in A. thaliana and A. arenosa. (a) Phylogenetic analysis of five MIR172 loci using miR172 stem-loop sequences originating in A. thaliana (At), A. arenosa (Aa) and three MIR172 loci in rice (Oryza sativa) (Os). Each A. arenosa locus has two corresponding A. thaliana loci, except for MIR172c that was absent in A. arenosa. Two rice MIR172 homologs are related to A. thaliana MIR172b and MIR172c, respectively. Brach lengths were calculated using bootstrap values with 1000 permutations. The unit of branch is indicated in the figure as the number of substitutions per 100 nucleotides. The nucleotide divergence rate between AaMIR172d-1 and AaMIR172d-2 was so low (0.3/100) that their branches were inseparable in the figure. (b) Stem-loop pairing of pre-mature miR172 sequences is mostly conserved between A. thaliana and A. arenosa, except that AaMIR172a-2 contains a deletion in the core miR172a so it is dwarfed. Dashed line indicates mature miR172 in AaMIR172a-1.
