Fig. 6.

Evolution of functional association of CIF C17 in flies. Cytosine single-site function logos are from Fig. 5, the tree topology is from Drosophila 12 Genomes Consortium (2007), and divergence dates are from Tamura et al. (2003) and Hennig et al. (1981). The three clades in which C17 became associated with tRNA^Asn genes are indicated by purple boxes on the tree, one of which (D. ananassae) also underwent the Asn-to-Lys anticodon shift previously reported in Rogers, Bergman et al. (2010) as indicated in top purple box at figure left. The stacked bar graph at figure right shows the frequencies of U17 or C17 across all tRNA^Asn genes in each genome showing that C17 was gained and/or lost in parallel and regained across all or mostly all tRNA^Asn genes at least three times during evolution of the Drosophila genus