Fig. 1: Spy-mac BE4max and Spy-mac ABEmax induce efficient C-to-T/A-to-G base editing in vivo.
From: Efficient base editing with expanded targeting scope using an engineered Spy-mac Cas9 variant
a Schematic representation of Spy-mac BE4max and Spy-mac ABEmax architecture. PIΔ, deletion of PI domain. b Average frequencies of C-to-T base editing at seven target sites that included NAAA and TAAN PAMs by Spy-mac BE4max in rabbit blastocysts. Data are presented as mean ± SEM. (n = ~6 blastocysts). c Frequencies of single C-to-T conversions at four target sites with TAAA PAMs by Spy-mac BE4max in rabbit blastocysts. Data are presented as mean ± SEM. (n = ~6 blastocysts). d–g Representative sequencing chromatograms of edited rabbit blastocysts at four target sites using the Spy-mac BE4max system. Targeted C·G to T·A conversions (red arrows). The relevant codon identities at the target site are presented under the DNA sequence. h Frequencies of single A-to-G conversions at four target sites with TAAA PAM by Spy-mac ABEmax in rabbit blastocysts. Data are presented as mean ± SEM. (n = ~6 blastocysts). i The target sequence at the Tyr-1 locus using the Spy-mac BE4max system. The PAM and sgRNA target sequences are shown in green and black, respectively. Target mutation (red). j Representative sequencing chromatograms from a WT and mutant rabbit (T1). The red arrow indicates the substituted nucleotide. The relevant codon identities at the target site are presented under the DNA sequence. k The predicted editing bar plot based on Sanger sequencing chromatograms from T1 by EditR. l Photograph of WT and Tyr-1 mutant (T1) rabbits at 1 month. m H&E staining of skin from WT and T1 rabbits. The green arrows highlight the melanin in the basal layer of the epidermis of WT rabbits. Scale bars: 50 μm
