To understand more about gene A it is crucial
that we find a way to control the gene so
that it will alter the genome.
Both RNAi and CRISPR accomplish this in similar
yet different and specific ways.
RNAi, or RNA interference, causes a silencing
effect by using two types of RNA to complete
the process, siRNA and miRNA.
miRNA and siRNA bind with a protein to create
a RNA Induced Silencing Complex or RISC for
short.
As this occurs the RISC includes a single
stranded segment of RNA which is called the
guide strand.
The process is specific as the guide strand
will have the perfect complementary bases
to some part of the mRNA of the gene that
is attempting to be silenced.
Once the guide strand base pairs with the
mRNA, the way that the gene becomes silenced
depends on the type of RNA the guide strand
is.
If it is a piece of siRNA that pairs to the
gene then it will degrade the mRNA, but if
it is a piece of miRNA then it will not allow
the mRNA to undergo translation.
This differs from CRISPR although it is another
method to control a gene and also has a specific
process.
CRISPR, or Clustered Regulatory Interspaced
Palindromic Repeats, is based on a natural
process used by bacteria protecting themselves
from viruses.
Bacteria would make a Cas9 which include two
pieces of RNA that were made when invading
DNA was found.
This enzyme can be used to cut DNA.
It knows where to do this as one of the pieces
of RNA will match the sequence of the DNA
and this is called the guide strand just how
RNAi also has a guide strand.
As this is the process in bacteria it can
also be used in living cells.
Cas9 will bind to an area in the nucleus of
a cell called PAM.
It will then unzip the DNA and the guide strand
will find its match and cut there.
The DNA will try to repair itself yet this
will cause mutations making the gene not work.
The specificity of this process is the fact
that a specific piece of DNA can be added
in and the DNA will base pair coding for a
specific trait.
A major difference between CRISPR and RNAi
is the fact that CRISPR can target multiple
genes at the same time.
In this case I would prefer to use CRISPR.
This is because a big difference between CRISPR
and RNAi is the fact that CRISPR can not only
turn off a gene yet it can add a specific
trait to the gene to find the exact effect
of the gene.
This allows the findings to be even more specific
to the exact trait scientists want to isolate
versus researching all of the effects a gene
might have.
Both techniques will achieve the same ending
of understanding more about gene A yet I believe
that the CRISPR method will give a more useful
answer to specific traits that are important.
