Genome
engineering, in the colloquial speech often denoted as “gene manipulation” is a
politically, socially and economically lively debated topic with proponents and
opponents coming from different lobbies. It is undisputed that Technologies
for making and manipulating DNA have enabled advances of great importance. One
of these technologies, the CRISPR/Cas9 is highly topical as it has been
declared by the Science-magazine as
the „Breakthrough oft the Year 2015“.
In the mid 2000s, scientists discovered so called CRISPRs (clustered
regularly interspaced short palindromic repeats) in the genome of Escherichia coli. Later on, CRISPRs have
been detected in various species of bacteria and archae (Doudna &
Charpentier, 2012). These sequences are part of the CRISPR/Cas system which acts
as a protection mechanism against viral invasion. CRISPR-associated proteins
(Cas) are able to bind and specific RNA sequences , the so called crRNA-repeat
sequence. This sequence is followed by a crRNA-spacer sequence which is
determining for its binding on the tareted DNA sequence. In turn, the enzyme
endonuclease Cas9 cuts this DNA in its close environment. With this ability,
the CRISPR/Cas system is able to find, cut and destroy viral DNA.
Due to the the ability of this system to edit specific sequences of the DNA
with a high precision it can be used as a mechanism to edit eukaryotic DNA as well,
as J. Doudna and E. Charpentier discovered in 2012. The simplicity of this
system makes it highly interesting as it only requires three components (crRNA,
trRNA and tha Cas9 enzyme).
Meanwhile, the CRISPR/Cas9 system has been successfully used to target important
genes in a broad variety of species including plants and humans (Reis, 2014). Presumably
the targeting and editing of genes in plants of agronomic interests is going to
be the most important application area. For example
the team around Dr. Cristobal Uauy tried to target a gene coding for a
plasma membrane protein which is thought to be involved in grain dormancy.
Despite of all the advantages this type of technology definitely has, its
usage is to handle with care. Concerning the near future of this technology,
the focus should lay on a suggestive regulation on the application of such a biochemical
“superweapon”.
References:
Doudna, J.A. & Charpentier, E. (2014). The new frontier of genome engineering with CRISPR-Cas9.
http://blogs.biomedcentral.com/on-biology/2015/11/30/using-crisprcas9-genetically-modify-crops/
https://www.neb.com/tools-and-resources/feature-articles/crispr-cas9-and-targeted-genome-editing-a-new-era-in-molecular-biology
Again a brief but yet precise summary of the important aspects of CRISPR/Cas9. Besides a few misspellings, solid and coherent wrinting in an appealing style. The appearance of Doudna in your reference list shows that you took your research seriously. Well done!
AntwortenLöschenHi Matthias
AntwortenLöschenAn impressing post with a great use of the English language. This is a promising effect. However, the scientific citations are suffering from it. You cited several studies, but not the scientific papers that belong to it, though in the reference section, you have a few websites indicated that may contain refernce to such content. Rather cite the scientific papers than websites in the next post!
Regards
Theo
Hi Matti
AntwortenLöschenI’m more than impressed! First of all, your blog entry is well-structured and written in a formal English. You describe the scientific aspects of CRISPR very well and give a good overview of the possibilities of using this powerful tool. Since this is a personal blog, you can also bring your personal opinion into it as an improvement suggestion from my side. (Maybe this is because I've read Johnny's blog before ;)
Hi Rastmat
AntwortenLöschenWell done! Your blog-post contains all the necessary parts, which where demanded. To summary such a complex topic in only 300 words is a very challenging task and you achieved it in a satisfactory manner.
I can see the relevance of Theos comment to quote more in a scientific way. I had to deal with the same problem. As the given time for these tasks is limited, we probably should learn to spend more time quoting than in texting.
By doing this blog-posts, I can assert I’m always getting faster, which leads to more time for quoting ;)