Researchers from the University of Freiburg, Germany, and partners developed a method called T-CAST to identify and mitigate off-target effects of TALENs. The details of the technique is published in Frontiers in Genome Editing.
T-CAST is based on a technique called CAST-Seq, which can be used to sequence all of the DNA in a cell. T-CAST uses CAST-Seq to identify all of the DNA that has been cut by TALENs. It then uses this information to identify off-target sites and to predict the TALEN pairing conformation that led to the off-target cleavage.
The study found that T-CAST was effective at identifying off-target effects of TALENs. It also found that T-CAST could be used to identify strategies to mitigate off-target effects. For example, the study found that TALENs that are made up of two different subunits, called obligate-heterodimeric TALENs, have fewer off-target effects than TALENs that are made up of two identical subunits.
The findings of this study are important because they could help to improve the safety of TALEN-based gene editing therapies. T-CAST could be used to identify and mitigate off-target effects of TALENs, which could help to reduce the risk of unintended side effects.
(Source: Crop Biotech Update, International Service for Acquisition of Agri-Biotech Applications. www.isaaa.org)