High-Throughput AAV Barcode Screening Identifies the Optimal Serotype for Efficient Transduction and CRISPR/Cas9 Gene Editing in Mouse Embryos

Adeno-associated virus (AAV) has emerged as a useful vehicle for delivering gene editing reagents in early embryos.However, the relative efficiency of different AAV serotypes in zygote transduction has not been systematically quantified.Here, we present the high-throughput, barcode-based in vitro screen of AAV serotype tropism in mouse zygotes using next-generation sequencing technology.We pooled 12 naturally existing AAV serotypes (AAV1-AAV12) and exposed mouse zygotes to the mixed library.Deep sequencing of embryos revealed that AAV6 achieved the highest transduction abundance among all serotypes, providing quantitative confirmation of its superior tropism in zygotes.Following the screening, AAV6 was utilized to deliver CRISPR-Cas9 elements into zygotes and observed efficient genome editing at the target locus in all embryos.Moreover, the infection of AAV6 in zygotes did not appreciably compromise embryo development or viability relative to controls, in agreement with prior observations that AAV transduction is well-tolerated by preimplantation embryos.In summary, our study provides a comprehensive, high-throughput validation of AAV serotype infectivity in mouse zygotes.