Geneticists dream of a day when they can repair defective human genes to wipe out diseases. That goal is decades off, but research on insects offers intriguing leads. This summer, scientists at San Diego State University restored the gift of flight to genetically defective fruit flies by injecting new genes into fly embryos. Doctors are taking note because defects in a similar human gene, which codes for the protein myosin, cause heart disease.
San Diego researchers caution that huge chasms separate insects from humans. They had to micro-inject up to 3,000 fly embryos to yield just one "cured" individual. Humans are more complex than flies, with whole batteries of genes coding for functions handled by a single insect gene. Still, laboratory chief Sanford Bernstein says there are important lessons. He can create the same kind of mutations seen in human genes, insert them into the fly, and then observe the muscle.