A Method for Precisely Identifying Modifications to Plant Mitochondrial Genomes by mitoTALENs.

The ability to transform plant mitochondrial genomes has many benefits. Although delivery of foreign DNA to mitochondria is presently very difficult, it is now possible to knock out mitochondrial genes using mitochondria-targeted transcription activator-like effector nucleases (mitoTALENs). Such knockouts have been achieved by a genetic transformation of mitoTALENs encoding genes into the nuclear genome. Previous studies have shown that double-strand breaks (DSBs) induced by mitoTALENs are repaired by ectopic homologous recombination. As a result of DNA repair by homologous recombination, a portion of the genome containing the mitoTALEN target site is deleted. The deletion and repair process cause the mitochondrial genome to become more complex. Here, we describe a method for identifying the ectopic homologous recombination events that occur following the repair of double-strand breaks induced by mitoTALENs.