Characterization of homozygous Foxn1 mutations induced in rat embryos by different delivery forms of Cas9 nuclease.

The Cas9 nuclease in protein form, when coinjected with the CRISPR gRNA (ribonucleoprotein) into a rat zygote pronucleus, can access the target genome site and induce double-strand breaks promptly, resulting in the efficient production of homozygous mutants.