Morpholino-mediated knockdown of chd4a , mta2, and the two RBBP4 orthologs rbb4 and rbb4l results in the reduction in regenerative outgrowth. (A-E) The dorsal half of fins was injected with control (A), chd4a translational blocking (B), chd4a splice blocking (C), mta2 translational blocking (D), and rbb4 + rbb4l translational blocking (E) vivo-morpholinos (MOs). The uninjected ventral half was used as an internal control to assess normal outgrowth. The left panels show fins shortly after injection at 3 dpa and the right panels show the same fins at 24 hours post-injection (hpi). The control MO does not affect regenerative outgrowth compared with the uninjected ventral side of the fins. Injection of the antisense MOs specific for chd4a, mta2, or the two RBBP4 orthologs rbb4 and rbb4l resulted in reduction in regenerative outgrowth compared with the uninjected side. (F) Percentage of regenerative outgrowth after MO injection relative to the uninjected control side of the fins. Error bars represent the SEM. n = 10. *P < 0.01.