Researchers have used precise gene-editing techniques to generate genetically modified monkeys.
Previous models of human disorders in monkeys were created using viruses to transfer genes, but this method lacks the precision needed to modify specific gene sequences. Xingxu Huang at Nanjing University in China and his colleagues turned to the CRISPR–Cas9 system, which uses a customizable RNA fragment to guide the DNA-cutting enzyme Cas9 to a specific site. The team altered the genome in one-cell-stage embryos of cynomolgus monkeys (Macaca fascicularis). This resulted in the birth of twins (pictured) with mutations in two target genes: Ppar-γ, which is involved in regulating metabolism; and Rag1, which is involved in immune function.
The results pave the way for producing primate models with specific mutations that more closely mimic human diseases.
For a longer story on this research, see go.nature.com/327cbd