CRISPR has been around for awhile and three years ago scientists created base editors, which is a version of CRISPR but more subtle. In
Science Magazine, Jon Cohen talks about a new found information that poses new problems for scientists involving these base editors. The base editors are suppose to help CRISPR target precise locations in DNA and instead of cutting the DNA they chemically alter one of the four bases in DNA with the enzyme
deaminase. However, scientists just realized that deaminase also has an effect on RNA. They noticed that cytosines were being converted to uracils.
To further confirm their findings, base editors were put into human liver and kidney cells which confirmed the altering of RNA. But wait... all hope is not lost. Scientists have found deaminases that work only on DNA or only on RNA leaving them confident they can figure out the off-target effects of the base editors. This research can really help with diseases such as Tay-Sachs and sickle cell since they are caused by a single mutation in one of the four DNA bases. This can be really useful stuff as long as other things aren't altered in the process.
This seems very promising because CRISPR/Cas9 can be inaccurate and effect other genes outside of the target region. I read that scientists are developing a new method of genetic engineering that has the ability to alter a single nucleotide at a time. To think of it metaphorically, CRISPR/Cas9 is like scissors and glue where DNA is being cut and replaced, but the new method is like a pencil and an eraser. Maybe that method will be much more accurate.
ReplyDelete