Gene Editing
Gene Manipulation
C.R.I.S.P.R.
C.R.I.S.P.R.
What is it and how does it work?
C.R.I.S.P.R stands for Clustered Regularly Interspaced Short Palindromic Repeats. It is a region found in bacteria made of DNA repeats and unique RNA spacers that store the DNA of viruses that threat the bacteria’s existence. Within the cells of the bacteria, after a new sequence containing the DNA of a certain virus is created it merges with an enzyme called CAS9 (CRISPR Associated protein) that cuts DNA. This intertwined system then floats around the cell looking for anything with the same DNA sequence as it does.
If one is found CAS9 will cut and disable the virus. This was discovered in 1987 by Yoshizumi Ishino but it wasn’t until 2012 when Jennifer Doudna and Emmanuelle Charpentier created a tool that replicates this action. Instead of a sequence containing the DNA of viruses, they instead created their own containing DNA of the body and a modified version of the CAS9 found in bacteria. The main advantages of using C.R.I.S.P.R over other gene editing tools like ZFNs and TALENs, are that it is 99% cheaper, more available and takes a lot less time to get results. C.R.I.S.P.R is also much more accurate than the other gene editing tools, such as ZFNs and TALENs, which means that it will be less likely for C.R.I.S.P.R to make a mistake when editing an organism’s DNA.
How can we use C.R.I.S.P.R?
C.R.I.S.P.R can be used either to insert genomes in the place of other genomes called a knockout or to add on genomes to a particular sequence defined as precise modifications. Editing genes using C.R.I.S.P.R can be performed on a human embryo or after birth. In order to generate a knockout, (replacing
desired genomes with new ones) a new RNA sequence must be created that will target whatever sequence is chosen. It then needs to be combined with CAS9 and the new RNA sequence. This will float around until it finds the target sequence where it will cut the existing sequence and replace it with its own.
The second method is adding a RNA sequence into one that is either broken or mutated. By inserting the desired sequence in through C.R.I.S.P.R into the broken pathway of the gene or mutated part the gene can then operate properly again. With the power of C.R.I.S.P.R we can cure diseases, strengthen our immune system, improve mental and physical features of our body and maybe stop. However, C.R.I.S.P.R is very early in its development and scientists have not yet attempted such experiments. Furthermore, C.R.I.S.P.R can also be used to edit the DNA on not only humans but other organisms, such as plants, insects and animals.
What can C.R.I.S.P.R do now and what is it capable of?
C.R.I.S.P.R in its current form isn’t as powerful and pinpoint as it claims to be. Occasionally the CAS9 enzyme will cut in the wrong place or it may create unintended irreversible mutations. At the moment it is has been used to create malaria-resistant mosquitoes, disease resistant livestock and for research into debilitating genetic diseases. Scientists predict that in the near future the possibilities of C.R.I.S.P.R include boosting strength and intelligence, preventing HIV and curing cancer and even designing the features of a child before they are even born.