A, several base changes predicted to stabilize the tau mRNA stem loop in vitro were made in both the WT and DDPAC (+14) stem loops. B, UV melting curves were generated for all 6 stem loop variants: DDPAC (○), DD-10C (△), DD-I17T (◊) WT (●), WT-10C (▲), and WT-I17T (♦). C, melting temperatures (Table 1) derived from the melting curves are plotted here of increasing stability. These nucleotide changes enhanced the thermal stability of both the WT and +14 mutated stem loops.