CRISPR/Cas9 genome editing

Cas genese encode for

nuclease or helicase proteins which can cut or unwind DNA

Spacer DNA

unique noncoding DNA that makes up much of all DNA little piece of viral DNA after CRISPR system cuts up genome of virus and reinserts that into its genome. Next time it gets attacked by virus, can mobilize the spacer and use it to disable virus's genome

Cas9

Enzyme is present in bacterial cell

Implications

-Alter DNA to prevent genetic diseases -Correct mutations in pre existing diseases- ex. cataracts -Artificial selection of traits in livestock and possibly humans (ex. no horns on cow or smarter offspring) -ethical concerns- altering DNA of babies, livestock, health implications of eating GMO's, is it humane?

Applications of CRISPR

Altering human genome in somatic cells such as stem cells or zygotes Also can correct mutations (cure disease) Livestock or Food crops Fast, simple, cheap Modify organisms to make biofuels Grow human organs in animals ex pigs Immunization of bacteria and alternative to antibiotics Genetic screens for disease

CRISPR

Clustered regularly interspaced short palindromic repeats. Consists of short repeated DNA sequences in a bacterial or archaeal genome, derived from previous bacteriophage or viral infection and conferring protection from future infection; considered a prokaryotic immune system.

Cas 9

Combination of proteins and RNAs to direct the cutting of DNA at a particular site OR a single protein. Through base pairing, the RNA associated with cas9 directs cas9 toward DNA to cleave. The bacteria then incorporates variable sequence from virus.

Cas9

RNA-guided DNA endonuclease enzyme associated with the CRISPR, produces single strand breaks in DNA

Intro

The discovery CRISPR- (clustered, regularly interspaced short palindromic repeats-CRISPR-associated proteins), is considered one of the most important breakthroughs in science within the past decade. Genome screening, manipulation and genome editing.

CRISPR (clustered regularly interspaced short palindromic repeats)

segments of prokaryotic DNA containing short receptions of base sequences. Each repetition is followed by short segments of "spacer DNA" from previous exposure to bacteria or viruses

In light of plans or ongoing research to apply CRISPR to human embryos in at least four labs in the US, labs in China and the UK, and by a US biotechnology company called Ovascience,

"scientists should avoid even attempting, in lax jurisdictions, germline genome modification for clinical application in humans" hese scientists support basic research on CRISPR and do not see CRISPR as developed enough for any clinical use in making inheritable changes to people.[120]

Research summary

-Current research: how crispr works, human embryo edited, malaria immune mosquito, curing cataracts, Organ transplant from pigs (all cited) -Implications of this research: Applications in medicine, agriculture, biotech (fuels) (all cited) -Challenges or Innovations: ethical and legality (cited)

Popular Articles (Magazines)

Are often written by journalists or professional writers for a general audience Use language easily understood by general readers Rarely give full citations for sources Written for the general public Tend to be shorter than journal articles

Scholarly Articles (Journals

Are written by and for faculty, researchers or scholars (chemists, historians, doctors, artists, etc.) Uses scholarly or technical language Tend to be longer articles about research Include full citations for sources Are often refereed or peer reviewed (articles are reviewed by an editor and other specialists before being accepted for publication) Book reviews and editorials are not considered scholarly articles, even when found in scholarly journals

How Crispr works

Bacteria and archaea have evolved adaptive immune defenses termed clustered regularly interspaced short palindromic repeats

Cas9

By delivering the Cas9 protein and appropriate guide RNAs into a cell, the organism's genome can be relatively cheaply cut at any desired location.

gene editing

CRISPR-Cas 9, an enzyme that cuts DNA in very specific places, allowing healthy DNA to bind to the now exposed area.

Benefits to CRISPR/CAS9 over alternative genome editing technologies

CRISPRs are much easier to design because they make a short RNA sequence that is paired to the targeted DNA sequence, rather than engineering an entire custom protein.

ethics

In April 2015, scientists from China published a paper in the journal Protein & Cell reporting results of an attempt to alter the DNA of non-viable human embryos using CRISPR to correct a mutation that causes beta thalassemia, a lethal heritable disorder.[121][122] According to the paper's lead author, the study had previously been rejected by both Nature and Science in part because of ethical concerns; the journals did not comment to reporters.[123] The experiments resulted in changing only some of the genes, and had off-target effects on other genes; the scientists who conducted the research noted that CRISPR is not ready for clinical application in reproductive medicine, and said to a reporter at Nature: "If you want to do it in normal embryos, you need to be close to 100%.... That's why we stopped. We still think it's too immature."[123] In December 2015, scientists of major world academies called for a moratorium on inheritable human genome edits, including those related to CRISPR-Cas9 technologies.[1

Spacer acquisition stage

When a microbe is invaded by a virus, the first stage of the immune response is to capture viral DNA and insert it into a CRISPR locus in the form of a spacer

The CRISPR/Cas system has been used for

gene editing (adding, disrupting or changing the sequence of specific genes)

CRISPR/Cas system

prokaryotic immune system that confers resistance to foreign genetic elements such as plasmids and phages,[4][5] and provides a form of acquired immunity CRISPR spacers recognize and cut these exogenous genetic elements in a manner analogous to RNA interference in

CRISPR-CAS

reduces the likelihood of repeat viral infection in bacteria. Once infected the first time, the bacterial protein as cuts up a viral genome into spacers that are inserted between CRISPR repeats. This allows the cell to recognize these sequences and mount a adaptive immune response if re-infected.