Splice Modulation Studies Using Reporter Mice

Exon-skipping therapy for Duchenne muscular dystrophy (DMD) recovers muscle function by inducing shorter but functional dystrophin protein using antisense oligonucleotides (ASOs) that modulate the pre-mRNA splicing of DMD transcripts to restore the disrupted DMD reading frame. Next-generation ASO should have appropriate sequences and modifications that induce exon skipping and ensure efficient delivery to target tissues. Conventional methods involve analyzing biopsied tissues using RT-PCR or immunoblotting to evaluate exon skipping or the expression of induced proteins. However, these methods are laborious and time-consuming, resulting in a low throughput. In this chapter, we present a novel evaluation method using reporter mice. Exon skipping induces the expression of fluorescent proteins enabling noninvasive monitoring. This in vivo method allows for a high-throughput evaluation of the efficacy of ASO-induced exon skipping.