Wait a second!
More handpicked essays just for you.
More handpicked essays just for you.
Don’t take our word for it - see why 10 million students trust us with their essay needs.
Recommended: An essay about CRISPR
CRISPR is a microbial nuclease mechanism involved in defense against invading phages and plasmids. The Loci of CRISPR in bacteria and viral hosts contain a combination of CRISPR-associated (Cas) genes and non-coding RNA elements capable of programming the specificity of the CRISPR-mediated nucleic acid cleavage. CRISPR is based on the protein CRISPR associated protein Cas, which bacteria and archaea wield as a tool to sever predatory bacteriophage's ( and viruses) DNA.
A breakthrough for the basic understanding of CRISPR defense mechanism was achieved by a group of researchers led by Barrangou, who showed that Streptococcus thermophilus can acquire some form of resistance against a bacteriophage by integrating a genome fragment of an infectious virus into its CRISPR locus (Richter et al 2013). CRISPR systems arm bacteria and archaea with a sequence-specific heritable ‘adaptive immune system’ that has a genetic memory of previous genetic invasion. A CRISPR cluster is a genomic DNA element made up of a string of 24-37 bp short repeat sequences that are divided by unique spacer sequences of similar length.
The sequences stem from a virus' genome, elucidating the genetic memory of previous infection. The second part of the CRISPR/Cas machinery is encoded in the Cas genes, and the Cas proteins attain its purpose within the immunity mechanism. The mechanism of CRISPR/Cas interference is of three phases (Appendix I). Firstly, resistance is acquired via the integration of short sequences from spacers (foreign genetic elements) into repetitive genetic elements known as CRISPR arrays. Secondly, transcription and processing of CRISPR arrays into small RNAs (crRNAs) by Cas proteins. Lastly, targeting of the invading phage or plasmid is m...
... middle of paper ...
...age fragments. The kit uses the Cel-1 nuclease that identifies and cleaves DNA mismatches from hybridization of wt and mutant sequences.
Conclusion
The prospects of CRISPR/Cas systems to function in genetic tools has been studied since its identification as a prokaryotic defense system. Less than a decade after its discovery, the first steps have been made, as sgRNA:Cas9 complexes are used for efficient gene silencing (Qi et al, 2013). The development of RGEN genome editing tools is only an aspect in which CRISPR/Cas defense system shows its prospect for biotechnological application. The establishment of RGEN genome editing tools further model organisms could simplify their future genetic manipulation (Richter et al 2013). For these reasons, the Science journal elected CRISPR gene-editing technique as the 2013 runner-up for the scientific breakthrough of the year.
In the book, Crispin: The Cross of Lead, the protagonist Crispin faces many conflicts throughout the book in which he must conquer in order to find who he really is. These conflicts change Crispin as a character over the course of the book, as he overcomes them to find out his true self. One conflict for Crispin is person vs society where he becomes known as a wolf’s head and does not have any friends, or family. This is until he meets Bear who helps Crispin overcome this conflict. For example, John Aycliffe tries to find Crispin, but helps him get away. As the story develops Crispin saves Bear from John Aycliffe, showing their friendship.
samples. In our experiment we learned the how to replicate tiny samples of DNA into usable
Arthur Bank, guest journalist for BioJournals, recently detailed that modifying viruses proves to be an effective w...
"Polymerase Chain Reaction (PCR) Fact Sheet." National Human Genome Research Institute. 10 Dec. 2007. National Institutes of Health. .
Every year, the rate of mortality increasing because most diseases may lead to death if not treated early. One of the methods that can be used to cure some diseases is by using the treatment known as gene therapy. Based on Pruitt’s (2008) study, numbers of inherited and acquired diseases were reduced since gene therapy has the ability to provide new treatments to cure them. According to Shi and Zou (2008), gene therapy is defined as expression of protein or interrupts the synthesis of protein in cell by transferring the genetic material into a host in order to treat or prevent a disease. Besides that, Kelly (2007) stated that an “abnormal” hereditary disease-causing gene in an individual’s cells and tissues is treated and used gene therapy by to replace them with a “normal” gene. Around 1970’s, idea to use “genes” as “drugs” for human therapy was originally from United States (Giacca, 2010). Moreover, there are some objectives in using the gene therapy as a treatment. First, gene therapy is used to cure or slow the progression of disease by introducing the genetic material into target cells and next objective is to aim at the direct correction of endogenous genetic defects by delivered some additional copies of a gene (Pruitt, 2008; Giacca, 2010). Furthermore, Yadav and Tyagi (2008) found that there are two types of gene therapy which are germline gene therapy and somatic cell therapy. As stated by Shi and Zou (2008), therapy that involved modification of any cells in a patient’s body is called as somatic cell gene therapy while germ line gene therapy is therapy that involved modifying of human eggs or sperms that pass genes on to future generations. Other than that, animal tissue culture is used to test the effective...
Imagine if there was a cure for cancer right at our fingertips… Gene therapy is attempting to achieve that goal by replacing a mutated gene, such as a cancer gene, with a healthier copy of it. However gene therapy is still very new in the medical field and as such comes with plenty of risks with one being that it may cause a tumor to grow. How can gene therapy act as a potential cure for cancer and what are the potential harms that can come out of treatment?
Then the sequence was loaded into Velvet where it was trimmed to the desired k-mer length for alignment and contig formation. Mitos and MEGA alignment Explorer were also used in order to get the DNA sequence to a
Sometimes genes can also be transformed by viruses that can extract a gene from one bacterial cell and inject it into another (3).... ... middle of paper ... ... This understanding must extend to the need to preserve microbial communities that are susceptible to antibiotics, so they will always be able to out-compete resistant strains.
The term ‘genetic engineering’ covers several methods of manipulating genetic material, otherwise known as genetic manipulation; recombinant DNA technology and gene therapy in humans(Atkinson, 1998). This technique is not only used for genetic transfer between plants; but, genes from non-plant organisms can be used as well. A known example of this is the transfer of the B.t gene found in corn and other crops. The B.t gene, or otherwise known as ‘Bacillus thurngiensis (Bt)’; is a naturally occurring bacterium that create proteins with crystals that are fatal to insect larvae (Whitman, 2000). These B.t genes have
The discovery of genome sequencing by Fredrick Sanger and his team of researchers in the early 70’s gave rise to one of the most empirical research methods that was ever to exist. This revolutionary research technique has allowed scientists to finally encode organisms down to their most basic properties; helping massively in our understanding of pathways, reactions and functions of organisms. The technique involves analysing the DNA of an organism’s genome and therefore all the genes that compose it. The DNA from an organism is run through an electrophoresis gel and the sequence produced is taken up and interpreted by a computer program to then present the nucleotide sequence of the organism. Genome sequencing of pathogenic organisms has lead to huge advancements in the fight against infectious diseases within human and veterinary medicine; three notably virulent infectious diseases of the veterinary world are bluetongue virus, equine strangles and bovine tuberculosis (Goodhead, 2012).
The birth of genetic engineering and recombinant DNA began in Stanford University, in the year 1970 (Hein). Biochemistry and medicine researchers were pursuing separate research pathways, yet these pathways converged to form what is now known as biotechnology (Hein). The biochemistry department was, at the time, focusing on an animal virus, and found a method of slicing DNA so cleanly that it would reform and go on to infect other cells. (Hein) The medical department focused on bacteria and developed a microscopic molecular messenger, that could not only carry a foreign “blueprint”, or message, but could also get the bacteria to read and copy the information. (Hein) One concept is needed to understand what happened at Stanford: how a bacterial “factory” turns “on” or “off”. (Hein) When a cell is dividing or producing a protein, it uses promoters (“on switches”) to start the process and terminators (“off switches”) to stop the process. (Hein) To form proteins, promoters and terminators are used to tell where the protein begins and where it ends. (Hein) In 1972 Herbert Boyer, a biochemist, provided Stanford with a bacterial enzyme called Eco R1. (Hein) This enzyme is used by bacteria to defend themselves against bacteriophages, or bacterial viruses. (Hein) The biochemistry department used this enzyme as a “molecular scalpel”, to cut a monkey virus called SV40. (Hein) What the Stanford researchers observed was that, when they did this, the virus reformed at the cleaved site in a circular manner. It later went on to infect other cells as if nothing had happened. (Hein) This proved that EcoR1 could cut the bonding sites on two different DNA strands, which could be combined using the “sticky ends” at the sites. (Hein). The contribution towards genetic engineering from the biochemistry department was the observations of EcoR1’s cleavage of
Marker assisted breeding (or marker aided selection) refers to the study of the trees’ genetic fingerprint (DNA) or more specifically the genetic variability of a species (variation in the DNA). Trees containing characteristics of interest, such as fast growth rate and disease resistance, can be selected using specific gene markers. Gene markers can be a single nucleotide insertion or deletion in the DNA that can be associated with the trait of interest. Using this information, tree breeders can predict the performance of trees and make early selections for turning over tree generations. They can also select the best parents to cross in order to produce good offspring.
The restriction enzymes SmaI cuts DNA vertically. This results in two DNA fragments with blunt ends. Next, the gene is spliced into a vect... ... middle of paper ... ... le by stopping illness but this process has also been vandalised for many uses which are not necessary.
In a recent study by Editas Medicine, they are working with CRISPR to prevent a blinding disorder called “leber congenital amarurosis” which is a rare inherited disease (Knapton, 2015). This disorder is due to a defect in a gene that encodes for a protein that is essential for vision, using CRISPR they are able to cut out the mutated areas. This is one example on how modifying DNA can be beneficial and why it should be accepted. Many inherited disorders like cystic fibrosis or Tay-Sachs. With parents having genetic screen tests they can provide a better future for their children and prevent them from a life with a
Gene therapy assists in explaining the nature of infectious diseases, in particular, the interactions between an invading microbes and their host’s immune defense system. A gene must be carried by a “vehicle”, or vector in order for the therapeutic gene to counterattack the disease. The use of vectors (genetically engineered retroviral) infect human genes, which overwrite defective genes and become functional again. The gene of interest is to efficiently infuse larger cells without activating an immune response against ourselves. “The immune system has developed means of detecting and killing the cells that harbors the invaders. All these stratagems are programmed into the genes of human ce...