First monkeys with customized mutations born

Helen Shen in Nature:

The ultimate potential of precision gene-editing techniques is beginning to be realised. Today, researchers in China report the first monkeys engineered with targeted mutations¹, an achievement that could be a stepping stone to making more realistic research models of human diseases. Xingxu Huang, a geneticist at the Model Animal Research Center of Nanjing University in China, and his colleagues successfully engineered twin cynomolgus monkeys (Macaca fascicularis) with two targeted mutations using the CRISPR/Cas9 system — a technology that has taken the field of genetic engineering by storm in the past year. Researchers have leveraged the technique to disrupt genes in mice and rats^{2, 3}, but until now none had succeeded in primates.

Previous attempts to genetically modify primates have relied on viral methods^{4, 5}, which create mutations efficiently, but at unpredictable locations and in uncontrolled numbers. Prospects for primates brightened with the emergence of the CRISPR/Cas9 gene-editing system, which uses customizable snippets of RNA to guide the DNA-cutting enzyme Cas9 to the desired mutation site. Huang and his team first tested the technology in a monkey cell line, disrupting each of three genes with 10–25% success. Encouraged, the scientists subsequently targeted the three genes simultaneously in more than 180 single-celled monkey embryos. Ten pregnancies resulted from 83 embryos that were implanted, one of which led to the birth of a pair with mutations in two genes: Ppar-γ, which helps to regulate metabolism, and Rag1, which is involved in healthy immune function.

More here. (Note: CRISPR is one of three most important biologic discoveries of the last century.)