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Cloning Essay

Decent Essays
Alyvia Orsini
Techniques in Cloning
CRISPR
CRISPR-Cas9, often called “CRISPR” is a genome-editing tool used in the field of genome engineering. CRISPR stands for Clustered Regularly Interspaced Short Palindromic repeats, and combined with Cas9, the two are an important part of a bacteria defense system. The goal of this technique is to target specific portions of genetic code and to edit the DNA at exact locations. CRISPR is natural to the bacterial cell’s immune system and provides protection against viruses. This allows researchers and scientists to modify genes in living cells and organisms (“Questions and Answers about CRISPR”, 2017).
In 1993, Fransisco Mojica was the first scientist to characterize the CRISPR locus, which were
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More recently, CRISPR has been used to edit human embryos, making inheritable changes to the human genome, editing crop genomes, and the first human trial was approved by the National Institute of Health in 2016 (“CRISPR Timeline”, n.d.). One of the main uses of CRISPR-Cas9 is to generate knock-out cells or animals, however modifications can be made to the Cas9 enzyme to selectively activate or repress target genes or purify specific regions of DNA. Before discussing how CRISPR works, it is important to understand its fundamental parts. There are two components of CRISPR, one being a “guide” RNA (gRNA) and the other being a non-specific CRSIPR-associated endonuclease, which is Cas9. The gRNA is synthetic RNA made up of a “scaffold” sequence for the Cas9-binding and a user-made nucleotide “spacer” sequence. The genomic DNA being addressed can be any 20-nucleotide DNA sequence as long as it meets certain conditions. This includes being unique compared to the rest of the genome and the target is present upstream of a Protospacer Adjacent Motif, or PAM. (“CRISPR/Cas9 Guide”, n.d.). Nonetheless, one of the many benefits of using CRISPR is its simplicity. When the CRISPR-Cas9 system is delivered to a cell, the gRNA binds to the target site through complementary base pairing. Then, the gRNA will show Cas9 where the target site is, allowing it to make a specific cut in the DNA double
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