article_snippet: A team of researchers has been customising a defence system used by bacteria and training this scissor-like machinery to recognise the HIV virus (pictured) CRISPR technology precisely changes target parts of genetic code .
article_snippet: Unlike other gene-silencing tools, a defence system used by bacteria and training this scissor-like machinery to recognise the HIV virus (pictured) CRISPR technology precisely changes target parts of genetic code targets the genome's source material and permanently turns off genes at the DNA level.
article_snippet: But unlike UV rays that can result in genetic alterations, a defence system used by bacteria and training this scissor-like machinery to recognise the HIV virus (pictured) CRISPR technology precisely changes target parts of genetic code causes a mutation at a precise location in the genome.
article_snippet: In this way, researchers can precisely turn off specific genes in the genome. '
article_snippet: To combat this problem, the team turned to a molecular defence system called CRISPR that bacteria use to cut up foreign DNA at specified spots.
article_snippet: Since its recent discovery, scientists have started using CRISPR to edit genes.
article_snippet: But the researchers were also intrigued by its defensive ability and wondered if CRISPR could be programmed to slice and destroy viruses inside human cells.
article_snippet: CRISPR uses bits of genetic material called guide RNAs to dictate CRISPR cuts, so scientists developed guide RNAs that bound to unique spots on the virus.
article_snippet: CRISPR can actually excise the virus out of the genome,' Liao says.
article_snippet: Having the CRISPR system in place, Liao and his colleagues showed, prevented an infectionCRISPR chopped up any copies of the virus before Liao and his colleagues could start replicating.
article_snippet: With that in mind, the team is studying the effectiveness of adding more guiding RNAs to the CRISPR mix so that the defence simultaneously recognizes more areas of the virus. '