Generation of conditional Acvrl1 knockout mice by CRISPR/Cas9-mediated gene targeting

This study aimed to generate mutant mice containing the Acvrl1 gene flanked with LoxP sequences to allow conditional deletion of Acvrl1 by the LoxP/Cre system. Such mice may facilitate the development of brain arteriovenous malformation (BAVM) models.

The CRISPR/Cas9 technique was used to edit Acvrl1. Two single guide RNAs (sgRNAs) with recognition sites on intron 3 and 8 and a donor vector that was homologous with the targeted gene and contained two LoxP sequences were designed and constructed. The in vitro-synthesized sgRNA, Cas9 mRNA and donor vectors were injected into mouse zygotes, which were then transferred into pseudopregnant mice. Neonatal mutant mice were identified by genotyping and sequencing.

Two mice with a floxed Acvrl1 allele were generated at a success rate of 8.7%. The target mice, which were healthy and fertile, were obtained through interbreeding.

CRISPR/Cas9 is a reliable gene-editing tool, and is able to efficiently modify Acvrl1 and create the target mice.