Figure 3. A Strategy for Creation of Knock-Out Marmosets. Generation of knock-out marmosets using engineered nucleases does not need naïve marmoset embryonic stem (ES) cells that can contribute to chimeric animals. (A) Synthesized mRNA encoding engineered nucleases that target a gene of interest are injected into fertilized marmoset eggs. (B) During the early embryonic stages, the engineered nucleases induce double-stranded breaks, resulting in frame-shift mutations due to a non-homologous end-joining mechanism. (C) Injected eggs are transplanted to the uterus of a surrogate mother and finally develop to knock-out marmosets.