Table 3. Development of rat embryos co-introduced to Cas9 nuclease protein and gRNA by microinjection or electroporation.

Methods	No. of embryos examined	No. (%) of 2-cell embryos	No. (%) of offspring	No. (%) of knockout offspring
Microinjection	40	19 (48)	13 (68)	10 (77)
Electroporation	25	25 (100)	17 (68)	17 (100)

Targeted gene: Tyr gene. Cas9 protein and gRNA (Integrated DNA Technologies, IA, USA) were used [43].