Comparisons of the sequences and putative secondary structures of trnR-CCG, trnR-UCG and trnSeC (tRNA-selenocysteine). A, primary sequences of Alsophila spinulosa trnR-UCG, Adiantum capillus-veneris trnSeC and trnR-CCGs from other six land plants. Dashed rectangle indicates anticodons. B, the putative secondary structures of Angiopteris evecta trnR-CCG,Alsophila trnR-UCG and Adiantum trnSeC. Dashed ellipses indicate anticodons.