A team of scientists in China is creating controversy with a new publication reported in the National Science Review, a Beijing journal. They inserted a human brain development gene into the genomes of a group of rhesus monkeys. After the genetically engineered monkeys were born and had a chance to grow, the researchers conducted tests that led them to conclude that the monkeys were performing better on memory tests than un-engineered monkeys.
“This was the first attempt to understand the evolution of human cognition using a transgenic monkey model,” Kunming Institute of Zoology geneticist and research leader Bing Su, commented to MIT Tech Review.
The researchers aimed to learn more about how the human brain develops. Several research groups have found that a gene called MCPH1 helps control the size of the human brain. Babies that carry dysfunctional copies of the gene are born with microcephaly - an abnormally small head.
In this work, the scientists injected a virus that carried the MCPH1 gene into rhesus monkey embryos, so that the gene would be inserted into the genome. Of eleven monkeys that were born successfully, five survived and grew older. They carried from two to nine copies of the gene. The scientists then conducted a variety of tests. They reported that the monkeys’ brains were a normal size. However, the genetically engineered monkeys had better memory and processing abilities. Their brains were also slower to develop, and grew at a rate that was more similar to human brains.
This work isn’t exactly poised to create a planet of smart apes. But some scientists are expressing concern about what they see as ethically dubious work.
“The use of transgenic monkeys to study human genes linked to brain evolution is a very risky road to take,” geneticist James Sikela, who performs comparative studies with primates at the University of Colorado, told MIT. He suggested that this research disregards ethical concerns about the animals and could lead to more extreme changes. “It is a classic slippery slope issue and one that we can expect to recur as this type of research is pursued,” he added. Most countries would not approve of this type of experimentation.
One scientist who assisted with an MRI portion of the study has decided that this research was “not a good direction.”
Su, however, told MIT by email that because monkeys and humans have 25 million years of evolutionary differences between them, this study is not harmful to the research subjects.
“Although their genome is close to ours, there are also tens of millions of differences,” he said. These genetically engineered monkeys are still simply monkeys and haven’t become something else. “Impossible by introducing only a few human genes,” he added.
Su isn’t stopping his efforts. He is looking to the next gene already, SRGAP2C, which is thought to have a major role in the rise of human intelligence.