Figure 2. Directed evolution and recovery of chimeric clones.

(a) Using a shuffled library based on adeno-associated virus (AAV) 1–6, 8, and 9, a directed evolution strategy was employed to select for an AAV capsid that can cross the seizure-compromised blood–brain barrier (BBB) and transduce cells in the areas of seizure influence. (b) Viable recovered clones that were tested in these studies. The scale at the top corresponds to the amino acid residues, with start sites for VP1, VP2, and VP3 indicated. A color-coding scheme is used to indicate the overall serotype composition at each location, and graded colors within each clone indicate regions of shared identity between neighboring serotypes. Where AAV1 and 6 are indistinguishable by amino acid sequence, a double stripe is drawn. Missense point mutations are shown as thin vertical lines, with the color corresponding to a serotype with that amino acid or a black line to indicate an amino acid not present in any parent. To the right of each amino acid map is the number assigned to that clone and the round from which it was recovered (in parentheses). wt, wild type.