Genome Manipulation Essay

Genome editing is a huge leap forward in science and medicine. Because of recent advances in technology, the study of genes and induced ‘point’ mutations have led to the discovery and advancement of methods previously used in order to mutate genes. The development of Clusters of Regularly Interspaced Short Palindromic Repeats (CRISPRs) and CRISPR associated system 9 protein (Cas9) technology is a hugely significant leap forward as this is a tool that could potentially be used for the research into and hopefully the treatment of a range of medical conditions that are genetically related. Cystic fibrosis (Schwank, G. et al, 2013), haemophilia and sickle cell disease are an example of some of the conditions that have the

From the science community perspective, the CRISPR-Cas system could reduce or even eliminate many of the difficulties researchers face when gene editing such as cost, duration and accuracy. Prior to CRISPR-Cas, gene editing was performed in “big labs” with experts

For many years biomedical researchers like myself have been trying to create more proactive ways to amend the genome for living cells. In more recent fieldwork studies there has been a new state of the art instrument based on bacterial CRISP in close works with protein 9 often referred to as CAS9 from the streptococcus progenies have possibly unlocked new data. The CRISP/CAS9 tries to manipulate the function of the gene using homologous recombination and RNA interference, but is set back because it can only provide short term restriction of the genes function and it’s iffy off- target effects.

The author gives a brief history of past genome editing but thoroughly explains the history and mechanism of the CRISPR technology. She elaborates on how the technology has already been used to cure diseases and speculates on its future uses and regulation.

Every few years, advancements in technology alter the way scientists do their work. Recently CRISPR-Cas9, a RNA useful for working organisms in the animal kingdom has proven itself beneficial on a gene-editing platform. After performing many abortive attempts to manipulate gene function, including homologous recombination and RNA interference, scientists have finally had a breakthrough with CRISPR-Cas9.

CRISPR is versatile in that any target sequence can be modified by simply altering the gRNA sequence. In addition, multiple genes can be edited at the same time with great specificity (Cong 88-89). The convenience and accessibility of CRISPR resourced have also allowed thousands of laboratories worldwide to study CRISPR in different ways, which has broadened the horizons of its biomedical and clinical implications (Collins et al 259). Overall, the ease and simplicity of CRISPR technology has allowed for a rapid increase in the understanding of genome editing, which will allow CRISPR to revolutionize how certain conditions will be treated.

The ability to engineer biological systems and organisms has an enormous potential for applications across basic science, medicine and biotechnology. Genome editing is a group of technologies that allow scientists the ability to change an organism’s DNA, which can provide better outcomes for health and disease control compared to natural immunity and mutations. Genome editing (gene editing) allows genetic material to be added, removed or altered at particular locations in the genome. A number of gene editing technologies have emerged in recent years with one of the most versatile and precise methods of genetic manipulation being Crispr-Cas9 (Steve scott,2016). The term Crispr-cas9, (clustered regular interspaced short palindromic repeats)

Research at Harvard’s Medical School Laboratory has developed CRISPR, which essentially is working on doing the job of editing out the genes we don’t want and putting in ones we do. At the moment, this is only being done with small animals like pigs, but Chruch and Yang firmly suggest that we aren’t far along from doing this with humans and that we have the technology; they say the wait is just getting the rest of the science community on board with the project. An interview through MIT Technology Review interviews Yang and the studies with Harvard noting,“By editing the DNA of these cells or the embryo itself, it could be possible to correct disease genes and pass those genetic fixes on to future generations. Such a technology could be used to rid families of scourges like cystic fibrosis. It might also be possible to install genes that offer lifelong protection against infection, Alzheimer’s, and, Yang told me, maybe the effects of aging” (MIT Technology Review). The technique of editing the genome mainly exists in the embryo, but of course this technology is still in its early stages and hasn’t had the highest success rates, reportedly only 20-40% of the time according the

Figure 2. Schematic illustration of generating Nf1-/- iPS cells from its Nf1+/- counterparts. (A) is the genotype of Nf1+/- iPS cells. (B) and (C) are two kinds of Nf1-/- iPS cells after Crispr/cas9 mediated NF1 genome editing in Nf1+/- iPS cells. In the presence of the repair template, Crispr/cas9 is able to introduce a nonsense mutation (c.94-96>TAA) into the exon 2 of NF1 genome via the homology directed repair (HDR). Without the repair template, random insertions and/or deletions may be introduced by non-homologous end joining (NHEJ). Nf1-/- iPS cells are to be generated by introducing

A simple but effective method is correctly designing gRNAs. Ideally, the target sequence must be a unique and nearly perfect homology to the gRNA with as little to no homology at other points within the gene sequence. Another potential strategy involves reducing the concentration of gRNA and Cas9 that are expressed in cells. However, this strategy is considered inconclusive due to inconsistent reporting. Some cell lines showed a large decrease in rates of off-target binding while others showed no effect. An increasingly promising method for improving specificity involves using a mutated nickase version of the Cas9 enzyme. This modified version contains only one catatylic domain and is used as a single nickase system capable of cutting a single strand of DNA. This results in a “nick” or single stand break rather then a DSB and is repaired by HDR. To further reduce the risk of off target binding, a double or dual nickase CRISPR system can be implemented. This system uses two nickases which bind to opposite strands of the target gene, generating a DSB. This system closely resembles the Fokl enzyme activation used in TALEN, in that off target effects are reduced because the probability of two off target nicks within the same region is very unlikely. When the DSB is made, activation of NHEJ is initiated; to further increase specificity and reduce off-target effects, the HDR mediated editing is advised for both nickase

The power to genetically modify the human genome is being held captive even though it holds the opportunity to cure genetic diseases. The CRISPR method offers “unparalleled potential for modifying the human

Biology, in all of its glory, is quite amazing. It has always existed and always will; it merely just waits for a human to attempt to understand it. This understanding has taken centuries, however it seems to increase with the years. A very popular topic amongst biologists today is the genome, understanding it, mapping it, comparing one organism’s to another and so on. With the understanding of this genome though, we as humans want to delve into it, tweak it, and manipulate it until it is perfection to our standards. A development has arisen that will one day provide ways to make precise, targeted changes to the genome of living cells (1). CRISPR- Cas9 is the development that many scientists believe will eventually change the face of

The CRISPR protein contains the Cas9 enzyme that uses a guide sequence within RNA to form base pairs with DNA target sequences. This allows the enzyme to break the DNA at a specific region in the strand (Doudna & Charpentier, 2014). In other words, the Cas9 acts as a pair of scissors in order to cut the DNA at a specific location so that parts of DNA can then be changed by adding in or deleting fragments of the genome. Because CRISPR-Cas9 programming is simple and has the capacity to recognize targets at multiple areas, this has granted for many exceptional developments to be made concerning the editing, modification, regulation, and marking of genomic loci precisely and

Numerous human genetic disorders, such as neurodegenerative diseases, occur because of genetic mutations in human cells. New genome editing tools – as of 2014 - such as transcription activator-like endonucleases (TALENs) or CRISPR/Cas9 further ease the precise generation of non-human primates (NHP) models for human diseases. Several of these NHP models displayed clinical manifestations like those of human disorders, in comparison with rodent models. These new techniques are efficient, as well as easy to conduct. They also exhibit a low rate of off-targeting, allow the knockout of multiple genes, and can create bi-allelic mutants.

Gene editing is not a new concept, however the recent development of the CRISPR/Cas9 gene editing technique has greatly simplified the process of gene editing for scientists. This powerful new technique has many applications in biomedical research and has the potential to treat genetic diseases [2]. All cells in the human body contain a copy of the human genome, which contains almost 25 000 genes. Each molecule of Deoxyribonucleic acid (DNA) is made up of two complimentary strands twisted into a double helix that is held together by hydrogen bonds. Genes are a blue print for the human body, giving it instructions on how to create essential proteins [3]. Due to major advances in technology, scientists and researchers have identified thousands of genes that code for certain diseases. Changing genes in cells is not an easy process, however it can be simplified by using the CRISPR-Cas9 system.