The Role Of Bacterial Defense Systems Against Viruses

CRISPR is a new gene-modifying tool that has the potential to treat numerous medical conditions by editing genes that are responsible for certain diseases. This technology is based on the ability of bacteria to destroy the DNA of invading viruses. Studies have suggested that this new technology can be applied to human cells, although the idea of chopping up regions of the human genome can be unethical and could even be harmful. In order for the treatment to be administered to a patient, a small piece of RNA and an enzyme that makes a cut in the DNA are delivered to the cells. A biotechnology company, known as Editas Medicine, located in Cambridge, MA, is already designing treatments for conditions of the blood and the eye using CRISPR. For

Once the complex was bound to the DNA, a cut would be made to eliminate and destroy the invaders. 83% of archaeal genomes and 45% of bacterial genomes (Shabbir, M. et al, 2016) were shown to be able to successfully utilize the CRISPR Cas9 system. These are very promising statistics, so it is no wonder that there has been such an advancement in the past few years to bring this technology to eukaryotic cells, mammalian cells and eventually human cells.

Since the 1980’s, scientists observed a unnatural patterns in some bacterial genomes. One DNA sequence would be repeated over and over again, with original sequences in between the repeats. They called this odd function “clustered regularly interspaced short palindromic repeats,” or CRISPR. This was confusing to all until scientists realized the unique sequences in between the repeats matched the DNA of viruses, specifically viruses that target certain bacteria. It turns out CRISPR is an important part in the bacteria’s immune system, which keeps harmful viruses around so it is recognizable and can defend against those viruses next time they attack for an example; kind of like a book one would keep around to look back on for help even though one does not need the book at the time. The second part of the defense mechanism is a set of enzymes called Cas or, CRISPR-associated proteins, which can precisely locate DNA and remove all of the invading viruses. Conveniently, the genes that encode for Cas are always sitting somewhere near the CRISPR sequences kind

CRISPR has been garnishing a lot of media attention recently and it is not just popular among the scientific community but also the general public. Several online news outlets and scientific journals have been talking about the significance CRISPR-Cas could have for the field of genetics and science as a whole. I even came across a Youtube video from The Verge, a tech channel that normally does reviews on new smartphones and laptops talking about CRISPR [15]. So why is CRISPR gaining so much attention both from the scientific community and the general public? The answer lies in the potential this technology possesses.

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.

CRISPR stands for Clustered Regularly Interspaced Short Palindromic Repeat, referring to the repeating DNA sequences found in the genomes of microorganisms. CRISPR technology allows scientists to make precise changes in genes by splicing and replacing these DNA sequences with new ones. Through these changes, the biology of the cell is altered and possibly affects the health of an organism. The possibilities are endless as this offers opportunities in curing deadly diseases, modifying genes, and changing humanity as we know it. Although bioengineering has been around since the 1960s, CRISPR is significant because of the comparative low costs and the ease of the procedure to

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.

The CRISPR Team was fortunate to be a part of the “Virus Documentary” (SciChannel) and conduct successful experiments discovering the activity of viruses. Through a series of test conducted by The CRISPR Team, it

In “Life the Remix,” Alice Park discusses the impact and influence CRISPR has on science as well as its potential and risks. CRISPR—“clustered regularly interspaced short palindromic repeats”—is a technique to alter DNA, virtually for anything involving DNA. Although there have been attempts to edit DNA, none were as cheap and simple as CRISPR. This technique, which is based on the immune system of a bacetria, revolutionizes genetics after the subsequent discoveries of the molecular scissors enzyme: Cas9 and a method to efficiently and accurately edit human DNA using CRISPR, explains Park.

Scientist Christopher Allen, a researcher in the environmental and radiological health sciences department studies the genes that are essential for repairing DNA inside our cells. According to him, when the repair process takes a rouge turn, the result can be cancerous. Allen would like to be able to make a side-by-side comparison with a cell that has a gene he thinks is important in the repair process, and one that is missing that gene. In order to execute this comparability, he has to modify the genome of a cell, which CRISPR-Cas9 is helpful for.

Ryland F. Young III’s article, “Secret Weapon,” begins by explaining the efficiency of CRISPR defense. Bacteria’s are infected by bacteriophages 1030 times a day. Bacteriophages mutate and undergo an unfathomable amount of genomic recombination that makes it difficult for bacteria to defend themselves from these viruses. Scientist discovered a new bacteria defense systems called CRISPR. This process in combination restriction-modification, restriction enzymes and apoptosis allows bacteria to protect themselves from invading viruses. CRISPR defense is effective because it forced bacteriophages to undergo intense recombination shuffling down to a scale of the size of CRISPR spaces, instead of just mutating. Though CRISPR defense is an effective

CRISPR loci are first identified in archaea and bacteria when they systematically drew attention from scientists with their biological function to fight phages and viruses (Hsu, Lander, Zhang, 2014). Structurally, a clustered set of Cas (CRISPR-associated) genes and a unique CRISPR array constitute the CRISPR loci. The CRISPR array was further comprised of short repetitive sequence interspaced by distinctive sequences (spacers) in correspondence with exogenous genetic bits (protospacer). The natural CRISPR systems in bacteria and archaea carried out their adaptive antiviral immunity by following a three-step mechanism, namely acquisition of spacers, crRNA biogenesis, and interference (Wright, Nuñez, Doudna, 2016).

Gene editing is one of the most researched fields of molecular biology, as manipulated genes deem possible studying the specific genes and their effects. In the past, there were several attempts to manipulate gene function, including homologous recombination, RNA interference (RNAi), zinc-finger nucleases (ZFNs) and transcription-activator like effector nucleases (TALENs). These past approaches are expensive and time-consuming to engineer as opposed to Crispr Cas9, limiting their widespread use. What the Crispr Cas9 technique offers, and biologists desire, is specificity: the ability to target and study particular DNA sequences in the expanse of a genome with ease of preparation as used in Fu et al. (2014) and Korkmaz et al. (2016).

CRISPR loci are first identified in archaea and bacteria when they systematically drew attention from scientists with their biological function to fight phages and viruses (Hsu, Lander, Zhang, 2014). Structurally, a clustered set of Cas (CRISPR-associated) genes and a unique CRISPR array constitute the CRISPR loci. The CRISPR array was further comprised of short repetitive sequence interspaced by distinctive sequences (spacers) in correspondence with exogenous genetic bits (protospacer). The natural CRISPR systems in bacteria and archaea carried out their adaptive antiviral immunity by following a three-step mechanism, namely acquisition of spacers, crRNA biogenesis, and interference.

CRISPRs are often associated with cas genes that code for proteins related to CRISPRs. The CRISPR/Cas system is a prokaryotic immune system that confers resistance to foreign genetic elements such as plasmids and phages[6][7] and provides a form of acquired immunity. CRISPR spacers recognize and cut these exogenous genetic elements in a manner analogous to RNAi in eukaryotic organisms. I vividly remember that cold November morning. The torrent of rain and the howling wind made it nearly impossible to see the road ahead towards Tehran’s International Airport. I sat silently and watched the water droplets race each other across the car’s window as the windshield wipers marked each passing second. At the moment I did not understand why my family had to leave our home and our country forever. The uncertainty of moving to and