This is DNA. It’s the blueprint for making living things,
from single-cell bacteria to plants to animals, including
to humans. It influences almost every part of your physical being: the shape of your nose, the color of your eyes, sometimes your likelihood of getting certain diseases. But what if science could redraw your body’s blueprint? What if it were possible to edit your DNA? Insert new sequences that change
inherited traits, or remove genes that cause disease? Well, now it is
possible. With CRISPR. CRISPR is a combination of a scissor-like
protein, such as one called Cas9, and a guide molecule. The molecule acts as a bloodhound, taking CRISPR on the hunt to specific sites within the genome. Once there, the protein cuts the cell's DNA on the spot. That completely disables the targeted gene. The cells then repair their DNA. They put in a new DNA sequence that the bloodhound also carried, or simply patch up the break caused by CRISPR’s molecular scissors. Enter tiny cellular machines called ribosomes. They translate the edited blueprint, skipping the disease-causing genes or producing healthy proteins that the repaired genes code for. CRISPR’s ability to repair may be most important at the beginning of life. Edit the genome of a very early embryo — one created by in vitro fertilization — and couples who carry disease-causing mutations may be able to have children who are spared
from them. Once a child is born with a genetic disease,
such as Huntington’s or Tay-Sachs, it is more difficult to use CRISPR
to treat it. It’s also being used to research and test
treatments for cancer, blindness, and liver disease, among others. But CRISPR isn’t just for humans. Scientists are already editing
mosquitoes’ genomes, hoping to stop the transmission of deadly
diseases like malaria. And the potential of engineering microbes
may open the door to a new world of medical and technological advances. When you can edit DNA’s blueprint, the possibilities
are vast.