Gene Editing -What Is It?
Gene editing or Genome editing is the new buzzword in the scientific world. Wild speculations about Gene editing are common-place. Claims such as it is going to cure every disease on the planet or how it is going to act as a tool for evil in the hand of criminals(this sentence seems incomplete , change the construction). It is important that we explore the topic of Gene editing and understand it’s nuances and future.
Genome editing, or genome engineering, or gene editing, is a type of genetic engineering in which DNA is inserted, deleted, modified or replaced in the genome of a living organism. (in-text citation is missing)
Genome editing was(remove “was”) pioneered in the 1990s, before the advent of the(more) common current nuclease-based gene editing platforms, however, its use was limited by low efficiencies of editing. (in-text citation is missing) Genome editing with engineered nucleases, i.e. all three major classes of these enzymes—zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs) and engineered meganucleases—were selected by Nature Methods as the 2011 Method of the Year. (cite the source or paraphrase the text)
Where is Gene Editing now
Not too long ago, CRISPR was a cryptic acronym — or, to some ears, a drawer to keep lettuce fresh. (in-text citation is missing) Today, CRISPR Cas9, the most popular form of powerful gene-editing technology, is widely used to accelerate experiments, grow pesticide-resistant crops, and design drugs to treat life-threatening genetic diseases like sickle cell anemia.
But CRISPR is not perfect. Base editors (think of them as gene-editing pencils) can rewrite individual DNA letters. They home in on specific areas of DNA and swap out certain bases — A, C, T, or G — for others. But after the swap, base editors—like the cytosine base editor that converts C•G to T•A — perform unwanted off-target edits. Until now, even the best CRISPR tool, SpCas9, could only bind to about one in 16 locations along DNA, leaving many genetic mutations out of reach. (in-text citation is missing) Liu, Richard Merkin Professor, vice-chair of the faculty, and director of the Merkin Institute of Transformative Technologies in Healthcare at the Broad Institute of MIT and Harvard, set out with his team to pinpoint those troubling and erratic CRISPR-independent off-target edits.
“That type of off-target editing can occur at random locations in the genome,” said Liu. “When you run the experiment 10 times, you get 10 different answers. That makes it so challenging to study.”(Write this sentence as “Liu said that this type of….)
CRISPR has another hurdle to overcome: its limited ability to access the entire human genome. “You can’t actually park Cas9 anywhere in the genome,” Liu said. “You can only park it in places that have a small constant sequence of DNA, called a PAM.” (in-text citation is missing)
Until now, the most common PAM was NGG, where “N” is any base. But two consecutive Gs only occur in about one in 16 places in the genome. (in-text citation is missing) “One out of 16 is bad odds,” Liu said, before calculating the exact probability — 6.25 percent — in a couple of seconds
Using a previous invention, phage-assisted continuous evolution (PACE), Liu and his team forced SpCas9 to evolve quickly, creating many new generations of the protein in about a week (without PACE, the process takes months or years). Their goal was to produce new SpCas9 proteins that had all the talents of their mom protein but greater versatility. Only proteins capable of recognizing PAM sequences without a G survived the Darwinian selection. (in-text citation is missing)
The future of gene editing
CRISPR technology has led to innumerable advances in our understanding of the human genome and genetically inherited diseases, however, it is not without imperfections. A newer technology, TARE (Toxin-Antidote Recessive Embryo), is being tested out in animal studies, which have(so) thus(remove “thus”) far been very promising. TARE genomic modification technology improves on CRISPR in two aspects: genetic expression of the modified gene and the ability to pass on the mutation to future generations.(Give reference)
TARE was developed for modifying the epigenetics of non-human species, but as it is a genomic editing technology, (it)can be used to test and modify any genome through the same mechanisms, including human.(Give reference)
CRISPR uses gene drives from genetic engineering to create the desired mutation in a few individuals. To spread this mutation, these individuals mate with a larger population, thus modifying the epigenetics of that species by passing on their DNA. In humans, it could remove and replace an allele that causes a disease.(Reference?)
In lab experiments, when fruit flies with TARE gene drives were released in cages of wild-type fruit flies, all the flies in the cage had the TARE drive in just six generations.(Reference?)
The researchers pointed out that resistance can indeed evolve with a TARE drive in the wild, especially in very large populations, but they believe it will take longer and evolve at a much lower rate, Messer said. The implications of using this technology to study human disease remain to be seen.(Reference?)
This article delves into a very relevant and interesting topic.However it seems a substantial part of it has been plagiarised. Please change the matter to write it in your own words and maintain copyright ethics. While a few important tools in gene editing have been discussed in detail , I would suggest adding a short introductory description for CRISPR , TARE and other genetic editing tools in order to give some suitable context to the reader, otherwise the observations on their workings may appear slightly incomprehensible to someone who is not well-acquainted with this field. Do give a few more relevant subheadings and use bold and underline in important sections. Also , I would suggest changing the title to make it more precise. Lastly , please give references for the factual sections. Not a single reference has been given. This is a science blog and references are extremely important for supporting the facts and observations stated in it. If you have any doubts regarding how to write a blog , please feel free to ask us.