From Science Daily – One way of discovering a gene’s function is to switch it off and observe how the loss of its activity affects an organism. If a gene is essential for survival, however, then switching it off permanently will kill the organism before the gene’s function can be determined. Researchers at Cold Spring Harbor Laboratory (CSHL) have overcome this problem by using RNA interference (RNAi) technology to temporarily turn off any essential gene in adult mice and then turn it back on before the change kills the animals.
In a study published on April 12 in the journal Proceedings of the National Academy of Sciences, the scientists demonstrated the feasibility of this approach by turning off a gene necessary for DNA replication in mice until the animals lost weight and were at the brink of death, and then successfully reversing these symptoms and rescuing the mice by turning the gene back on.
The ability to regulate gene activity this way in animals “will not only help in pinpointing time frames during which essential genes are important during development, but will also be tremendously useful in cancer or other disease-related research,” says CSHL Professor and HHMI investigator Scott Lowe, Ph.D., who co-led the team along with Professor Bruce Stillman, Ph.D., CSHL’s president. “We could, for example, first allow tumors to grow in mice, then shut off a gene that we think might be a good therapeutic target to test whether it saves the animals,” Lowe explains.