Recently, the scientists from the Neuroscience Research Institute at Peking University published the paper Development of a CRISPR-SaCas9 system for projection-and function-specific gene editing in the rat brain in Science Advances. This study achieved projection- and function-specific gene editing in the rat brain by utilizing the CRISPR-SaCas9 system coupled with anterograde/retrograde AAV vectors and activity-dependent cell-labeling techniques.

In the study, researchers used an amplicon-based method to amplify the on-target and off-target loci, and the libraries were subject to sequencing on DNBSEQ-G50 afterwards. Deep sequencing analysis revealed that most of the off-target sites exhibited indel generation at least two magnitudes lower than that of corresponding on-targets (Figure.1). Using deep sequencing, it also confirmed indel formation in the targeted cbp locus at the single-cell level (Figure.2). Consistent with previous in vitro studies, SaCas9 was highly resistant to DNA mismatching, thus ensuring a high targeting specificity in vivo.

Figure 1. Cleavage levels at putative genomic off-target loci containing fewer than five mismatches (white cells) for cbptargets 1, 4, and 5 were analyzed by deep sequencing.

Figure 2. Graphical representation of the rat cbp locus showing gRNA target location. Targeted genomic locus is marked as blue. PAM sequence is marked as red.

DNBSEQ-G50 is a compact and flexible benchtop genetic sequencer. It supports hybridization-based/multiplex PCR-based targeted sequencing, small whole genome sequencing, and low-pass whole genome sequencing, etc. At present, a series of studies based on the sequencing data from DNBSEQ-G50 have been published. In particular, the study of novel coronavirus transcriptome using DNBSEQ-G50 was recently published in Cell to provide a reference and basis for follow-up research by scientists worldwide.

Tip 1 Featured papers published with data from MGISEQ-200 (DNBSEQ-G50)

[1] 一例基孔肯雅病毒和寨卡病毒混合感染病例的发现.华南预防医学.

DOI: 10.13217/j.scjpm.2019.0481

[2] Development of a CRISPR-SaCas9 system for projection and function-specific gene editing in the rat brain. Science Advances.

DOI: 10.1126/sciadv.aay6687

[3] The architecture of SARS-CoV-2 transcriptome. Cell.

DOI: 10.1016/j.cell.2020.04.011

Tip 2 Best Practice of MGISEQ-200 (DNBSEQ-G50)  

Remark: DNBSEQ-G50 retains its original product name MGISEQ-200 in China and certain overseas markets.