Using CRISPR, new technique makes it easy to map genetic networks

The CRISPR-Cas9 protein (above) allows researchers to inactivate individual genes in the genome, using a guide RNA sequence that matches the target gene. These guide RNAs are paired with nucleotide barcodes in a new and fast technique to map genetic networks called CRISPR interference with barcoded expression reporter sequencing, or CiBER-seq. CRISPR-Cas9 makes it easy to knock out or tweak a single gene to determine its effect on an organism or cell, or even another gene. But what if you could perform several thousand experiments at once, using CRISPR to tweak every gene in the genome individually and quickly see the impact of each? A team of University of California, Berkeley, scientists has developed an easy way to do just that, allowing anyone to profile a cell, including human cells, and rapidly determine all the DNA sequences in the genome that regulate the expression of a specific gene. While the technique will mostly benefit basic researchers who are interested in tracking the cascade of genetic activity - the genetic network - that impacts a gene they're interested in, it will also help researchers quickly find the regulatory sequences that control disease genes and possibly find new targets for drugs. "A disease where you might want to use this approach is cancer, where we know certain genes that those cancer cells express, and need to express, in order to survive and grow," said Nicholas Ingolia, UC Berkeley associate professor of molecular and cell biology. "What this tool would let you do is ask the question: What are the upstream genes, what are the regulators that are controlling those genes that we know about?" Those controllers may be easier to target therapeutically in order to shut down the cancer cells.