SRA

A missense mutation of collagen type VIII alpha 2 chain (COL8A2) gene leads to early onset Fuchs' endothelial corneal dystrophy (FECD), which can cause blindness through progressive loss of corneal endothelial cells. We established a novel procedure for achieving structural and functional rescue of the post-mitotic corneal endothelium without surgery, using CRISPR/Cas9-based postnatal gene editing in a mouse model of FECD. A single intraocular injection of an adenovirus encoding both the Cas9 gene and guide RNA (Ad-Cas9-Col8a2gRNA) at a titer below the cytotoxic threshold, efficiently knocked down COL8A2 protein expression in corneal endothelial cells, prevented endothelial cell loss, and rescued corneal endothelium pumping function in adult Col8a2 mutant mice. Here, to determine the indel rate in mouse corneal endothelium, we performed deep sequencing of PCR products (including the target site) amplified from genomic DNA of corneal endothelium. We found that the indel rate was 23.7 ± 4.5% in mouse corneal endothelium. Most insertions were 1bp insertions (19.8 ± 4.0% in total reads), while 2bp deletions were the most frequent (1.0 ± 0.3% in total reads). We moreover found that A or T insertion was predominant, with the proportion of A:T:G:C being 48.7 : 44.6 : 1.8 : 4.9. Overall design: gRNA target site was amplified by PCR, and indel rate was determined by deep sequencing