Fig. 4

Targeted CRISPR/Cas9 disruption of copb1 exon 8 generates a range of insertion-deletion changes in vivo. Xenopus tropicalis copb1 has 21 exons, including an untranslated first exon (a). CRISPR/Cas9 directed indel formation disrupting X. tropicalis exon 8 using 2 sgRNAs (red: sgRNA3 and sgRNA4 (b)) results in homozygous frameshift and splice changes akin to those identified within the patient subpopulation. Genotyping analysis of X. tropicalis crispants details the range of indels across three groups of 10 pooled tadpoles (NF41) injected with sgRNA3 following PCR amplification and Sanger sequencing of subclones (c). The 41-bp deletion observed in gDNA subclones extends into the intronic region and is proposed to induce exon 8 skipping in crispant X. tropicalis tadpoles. Total RNA was obtained from 4 groups (un-injected control (1), copb1 sgRNA 3 crispant set 1 (2) and copb1 sgRNA 3 crispant set 2 (3), injected control (4)) of 10 pooled individuals as outlined in Guille 1999 [51] and cDNA synthesised using Primer Design’s Reverse Transcription Premix 2. Amplification across the copb1 region of interest revealed a band at 382 bp (exons: 7, 8 and 9) and an additional band in crispants at 262 bp (exons: 7 and 9, Additional file 1: Fig. S1D)