CRISPRs Enlisted to Study Mutations Across an Entire Mammalian Genome

Scientists at the Wellcome Trust Sanger Institute have developed a technique to create a comprehensive library of mutations across all genes in the mouse genome. This library can be used to examine the role of every gene in different cell types, the researchers say.

CRISPR technology uses the DNA-cutting enzyme Cas9, with the help of a guide RNA sequence, to find and modify genetic targets. Scientists engineer multiple new guide RNAs using standard molecular biology techniques. This makes for a much faster and efficient method to modify the genome of any cell type in any species, according to the Wellcome group.

The team, which published their results online (“Genome-wide recessive genetic screening in mammalian cells with a lentiviral CRISPR-guide RNA library”) in Nature Biotechnology, found that 50 of 52 guide RNAs tested successfully cut both copies of the genes. The high success rate for these engineered guide RNAs seems to be consistent across many cell types, which led them to create a library of guide RNAs targeting every gene in the mouse genome.

“We designed 87,897 guide RNAs (gRNAs) targeting...