There in germ line cells, where CIRSPR can be

There are a number of
methods that biologist can employ to edit genes. The most powerful and
versatile method currently is the CRISPR/CAS9 technique. CRISPR stands for
clustered regularly interspaced short palindromic repeats. The power of CRISPR
comes from its simplicity and diversity. CRISPR is an enzyme that causes double
strand breaks (DSBs) in DNA in precise locations. The way it finds the correct
location to induce the DSB reminds me of how RNA polymerase and TFs work. The
CRISPR is introduced into the cell with a guide RNA (gRNA). The gRNA is a 20-nucleotide
sequence, giving it extreme precision in locating a specific locus on the DNA.
Once the gRNA finds the locus on the chromosome, it recruits the Cas9 (crisper
associated protein 9, a form of endonuclease) to the DNA strand kind of like how
a sigma subunit or other TF binds RNA polymerase to a specific site. Once the
Cas9 is bound to the DNA it then proceeds to catalyze the DSB, leaving sticky
ends behind at the cleavage sites. A new strand of synthesized DNA can then be
introduced into the gap, or an existing strand can simply be deleted. NHEJ
(non-homologous end joining) DNA repair mechanism is then implemented to rejoin
and ligate the sticky ends. Delivery methods for CRISPR vary extensively.
Methods include such things as viral and non-viral vectors, transfection,
electroporation, and microinjection (1).

The practical
applications of the CRISPR technique are numerous. There have been over 3,500
published reports using CRISPR in the last couple years alone (1). I only have
space to discuss a few uses of this tool. 
One of the leading areas of study for the application of CRISPR is in
germ line cells, where CIRSPR can be used to correct genetic abnormalities such
as inherited retinal degeneration, as just one example (2). Another area that
has received a lot of attention lately is the use of CRISPR in conjunction with
gene drives to eliminate such diseases as malaria, which use mosquitos as a
vector to infect humans. A gene drive, at least theoretically, gives the
selected gene 100% inheritance rate by incorporating the genes that create
CRISPR proteins and gRNAs into the host genome. The goal with mosquitos is to
engineer a gene that makes the mosquitos resistant to the malaria-causing
parasite called plasmodium parasite. With the help of gene drive, this parasite
resistant gene could proliferate to the point where all mosquitos within the
target species carry it, completely nullifying the vector for the parasite, and
eliminating malaria. This method is also being investigated with regard to a
number of other diseases that use mosquitos as vectors (3). Many methods for
controlling insect vectors have limited efficacy, whereas CRISPR technology in
conjunction with gene drives have the potential for near complete efficacy. Another
potentially use for CRISPR technology is for the investigation of neural
diseases. CRISPR can be used to create neural models of human diseases within
animals such as mice in order to conduct research that could not be done on
humans (4). This research focuses primarily on age related brain diseases such
as Alzheimer’s and huntingtins diseases. Not only can it be used to model these
diseases in animals, but once the diseases are better understood, it could
potentially be used in human germ line cells to eliminate the disease in vitro,
or in the zygote.

We Will Write a Custom Essay Specifically
For You For Only $13.90/page!


order now

In summary, CRISPR
technology is a revolutionary tool in the field of genetics and genomics. It is
very easy to use compared to other similar tools. The uses for the tool vary
extensively, and we have probably only begun to scratch the surface of
practical applications for it.