RNA-Guided Nucleases: A New Era for Engineering the Genomes of Model and Nonmodel Organisms

In 1946, H. J. Muller was awarded the Nobel Prize in Medicine for his discovery with Drosophila melanogaster , some 20 years earlier, that exposure to X-rays caused mutation ([Muller 1927][1]). This led to the identification of a large number of Drosophila mutants and chromosome rearrangements, many