Milky medicine

Researchers at the University of Pennsylvania have used gene therapy to cut significantly the time it takes to breed goats that can make therapeutic proteins, such as insulin and anticancer compounds, in their milk. Team member Ina Dobrinski explains the potential, "Having an easier way to harness nature's power to produce large quantities of specific proteins in milk could increase the availability of drugs for people who could otherwise not afford these treatments," she says. The researchers engineered goat sperm using a modified adeno-associated virus to insert a gene for a specific protein and then used these modified sperm in a breeding program to produce female offspring that make the protein in their milk.