Editing the claims

While the inventors of CRISPR tussle over ownership of the gene editing technology, Cellectis S.A. thinks it has a trump card that the winner of the CRISPR dispute will need to license in order to operate. The company owns a newly issued U.S. patent covering an enzyme class used in most methods of gene editing, but now faces a long slog of outplaying its opponents, who have wasted no time in challenging the claims.

The major systems for editing genes -- CRISPR, transcription activator-like effector nuclease (TALEN) and zinc finger nuclease (ZFN)-based editing -- all depend on an endonuclease to cut the target DNA site, but differ by the precise enzyme involved...