CRISPR Array

More recently, Kang et al have employed a different approach using a non-viral delivery method for CRISPR-Cas, known as the

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

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

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

CRISPR or Clustered Regularly Interspaced Short Palindromic Repeat, is used to change the DNA. Today, as humans, we have learned how to use CRISPR for what we want it to do. This is a major break in what we know about DNA. For the future we are looking at how we can change DNA and control what the DNA changes to.

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

Scientist Francisco Mojica was the first scientist to characterize a CRISPR locus in 1993, at the University of Alicante in Spain. Mojica studied CRISPR throughout the 1990’s and early 2000’s, and in 2002 the term CRISPR was first used in print by Ruud Jansen. Later, in 2005, Mojica discovered that sequences he discovered matched sections of genes from bacteriophage, which led him to hypothesize that CRISPR is actually an immune system from the bacteriophage. His hypothesis was indeed correct. Also in 2005, Cas9 was discovered by Alexander Bolotin, at the French National Institute for Agricultural Research while he was researching recently sequenced bacteria. Bolotin found that a CRISPR locus was similar to others that had already been discovered,

Even though CRISPR/Cas9 was just discovered around 4 years ago, the CRISPR/Cas system itself was first observed in bacteria (E.coli). It was what CRISPR was doing in the bacteria that makes it so unique. CRISPR stands for, “clustered regularly interspaced short palindromic repeats”. This means that there are going to be short sequences of DNA bases that will read the same forward and backwards. In-between these short sequences will be spacer DNA. Unlike the palindromic sequences, the spacer DNA will have sequences

CRISPR-cas9 allows researchers to edit part of the genome by inserting, deleting, or altering sections of the DNA sequence. The CRISPR-cas9 system consists of two key molecules: Cas9 and single-guide RNA (sgRNA). The enzyme Cas9 is ‘guided’ by sgRNA to the DNA sequences where it cuts the two strands of DNA at the specific location in the genome. Endogenous DNA repair mechanisms try to repair the breaks in both strands which then leads to indels that can cause mutation in the target gene. This process is shown in Figure 1.1. To determine whether CRISPR–Cas9 can be used to understand gene function in human preimplantation development, the POU5F1 gene that encodes the development regulator OCT4 was selected as the target. It was predicted that

infection by viruses. When a bacterium identifies a threat from a virus, it generates two types of

Cas9 has been well studied. It belongs to the class II CRISPR/Cas system which is the main protein involved in small interfering CRISPR RNA (crRNA). CRISPR RNA often leads to the silencing of invader viruses and plasmids [72, 85]. Several in vitro surveys have shown that Cas9 is guided by gRNA composed of chimeric RNA. Chimeric RNA is composed of crRNA and tracrRNA. They are sufficient to

CRISPR is an acronym for Clustered Regularly Interspaced Short Palindromic Repeat, which signifies to the distinctive organization of partially palindromic, short repeated sequences of DNA that are found in genomes of microorganisms, such as bacteria. While CRISPR sequences are seemingly harmless, these sequences are actually an essential element of the immune system of many simple life forms, such as microorganisms. The immune system is responsible for defending the health and well-being of many organisms within the body. Just as in humans, viruses, which are small infectious agents, can invade bacterial cells. If a bacterial cell where to be threatened by a viral infection, the CRISPR immune system can prevent the attack from the infection

The RNA-guided CRISPR-Cas9 system has revolutionized genetic engineering by allowing targeted genomic modification through the simple design of a 20 base pair guiding sequences. This groundbreaking technology utilizes a short guide RNA (sgRNA) to direct the Cas9 nuclease to a specific genomic locus through complementary base pairing. The guide RNA or sgRNA is responsible for the specificity of the CRISPR-Cas9 system, and several consideration need to be taken during its design process. In bacteria and archaea, the crRNA and tracrRNA form a complex which acts as the homing device for directing the Cas9 nuclease to the invading foreign genetic materials. The tarcrRNA 's scaffolding ability along with the specificity of the crRNA can be

Every year approximately 4 million babies are born, of those 4 million babies about 3 to 4% are born with a genetic disorder or a birth defect. Imagine, if our doctors and scientist were able to develop a mechanism to that would allow alterations in the genome of these children and adults alike. Dating back to 1987, such mechanism was first described by Dr. Yoshizumi Ishino while he was studying Escherichia coli or E.coli (ISHINO et al., 1987). This newly discovered system is called CRISPR, which stands for clustered regularly interspaced short palindromic repeats. Currently, many biotech companies are beginning in for the development and application of CRISPR for genome engineering.

There are three types of CRISPR systems. The Type II CRISPR system (where the interface is mediated by a single large protein in conjunction with crRNA) is the simplest of the three and it is this one that has been the basis for genome editing.