A new CRISPR/ Cas system has been identified, which may better the precision of genome engineering (techniques used in order to modify the genetic information).
CRISPR/ Cas9 has already been used by scientists in order to edit the genome of livestock, crops, and even human embryos. Although CRISPR is a much better method that the previous ones, scientists want to improve even more. They analysed the Cpf1 enzyme – which is different from Cas9 – from about 16 types of bacteria. What they found was that Cpf1 could be used in order to cut human DNA.
Feng Zhang and his fellow researchers from the McGovern Institute for Brain Research at Massachusetts Institute of Technology (MIT) and the Broad Institute of MIT and Harvard, conducted a study in which they demonstrated how the new CRISPR system worked.
“The paper shows that Cpf1 can be harnessed for human genome editing and has remarkable and powerful features,” stated Eric Landen, director of the Broad Institute and one of the leaders of the new project.
The CRISPR/ Cas9 system was first used for mammalian genome engineering in 2013. This particular system can be found in a wide variety of archaea and bacteria, which use it in order to protect themselves from viruses. The enzyme Cas9 is used by the CRISPR/ Cas9 to cut DNA.
In the new study, the researchers tried to find other enzymes that could be used in genome editing. For that, they analysed many CRISPR systems that could be found in a variety of bacteria. Zhang and his colleagues found the Cpf1 enzyme in two bacteria: Lachnospiraceae and Acidaminococcus.
The Cpf1 system differs from the Cas9 in certain aspects. For instance when Cas9 cuts DNA, it leaves dulled ends on the DNA strands which may suffer mutations once they are rejoined. When the scientists use the Cpf1 system to cut the strands the enzyme leaves overhangs on the ends of the strands. That makes it possible for DNA sequences to be inserted more accurately.
Zhang and his team of researchers are now working on improving the way in which a DNA sequence is replaced. They are hoping that by using the Cpf1 system, such insertions of DNA sequences will become more frequent.
Image Source: news.mit