– [Narrator] Our genes
determine many aspects of our health and diseases.
Some diseases are linked to a single gene, like sickle
cell anemia, cystic fibrosis, and Huntington’s.
Changes to one gene can lead to disease, But other conditions, like
cancer, are much more complicated and involve the interplay of many genes. The genetics of these diseases
is like a tangle of wiring scientists can’t see, with many switches controlling many light bulbs. Understanding these tangled
connections can be daunting, but may hold clues to treating diseases. You may have heard of
CRISPR, a way for scientists to target specific DNA
sequences and change them. CRISPR is like an electrician with an assignment and a wire cutter. Scientists send CRISPR into
cells to disconnect a piece of DNA.
That gives scientists some clue as to what a gene does, but it doesn’t reveal the whole story. So scientists train CRISPR
to be a better electrician. UCSF created technology that
replaces CRISPR’s wire cutter with a new tool kit.
CRISPRa to switch genes on, and CRISPRi to turn them off. Other tools can make genes
sensitive to light or track them with fluorescent tags to
visualize them in living cells. The changes are reversible
and multiple changes can be made at once, letting
scientists test the functions of different genetic elements. This is how CRISPR works inside a cell. The classic CRISPR system
consists of two components: A guide RNA that targets
a specific DNA sequence and the Cas9 protein, the wire cutter. To give CRISPR more
powers, UCSF scientists created a mutated version
of Cas9 called dCas9 that doesn’t cut DNA but
instead, swaps in different tools that can be used to dial up or dial down gene expression levels. Scientists are already
using the new CRISPR tools to study diseases like cancer and obesity, lighting the way for new genetic
treatments in our future. (light, happy music)