100% satisfaction guarantee Immediately available after payment Both online and in PDF No strings attached
logo-home
Lecture Notes on the CRISPR/Cas module (MCB2023S) $7.08   Add to cart

Class notes

Lecture Notes on the CRISPR/Cas module (MCB2023S)

 7 views  0 purchase
  • Course
  • Institution

Summarised lecture notes outlining the CRISPR/Cas system. Contents can be seen on the first page.

Preview 2 out of 11  pages

  • November 8, 2021
  • 11
  • 2021/2022
  • Class notes
  • Suhail rafudeen
  • All classes
avatar-seller
CRISPR
CRISPR.......................................................................................................................................................... 1
OVERVIEW.................................................................................................................................................... 2
CONCEPT BEHIND CRISPR/CAS:..............................................................................................................................2
TYPICAL STRUCTURE...............................................................................................................................................3
STAGES OF THE CRISPR/CAS SYSTEM............................................................................................................. 4
STAGE 1: SPACER ACQUISITION (IMMUNIZATION/ADAPTATION).....................................................................................4
Protospacers & PAM:......................................................................................................................................4
STAGE 2: CRNA EXPRESSION & PROCESSING..............................................................................................................5
STAGE 3: CRISPR INTERFERENCE (TARGETING/IMMUNITY)...........................................................................................5
MECHANISMS OF ACTION............................................................................................................................. 7
TYPE II SYSTEM CRISPR/CAS 9...............................................................................................................................7
Spacer Acquisition..........................................................................................................................................7
cRNA expression & processing........................................................................................................................7
CRISPR Interference/Targeting.......................................................................................................................7
GENOME EDITING......................................................................................................................................... 9
Development of CRISPR as an Antiviral Strategy to Combat SARS-CoV-2 and Influenza...............................9
Guide RNA – sgRNA........................................................................................................................................9
CRISPR/CAS NUCLEASE RNA-GUIDED GENOME EDITING USING NHEJ.........................................................................10
CRISPR/CAS NUCLEASE RNA-GUIDED GENOME EDITING USING HDR FOR GENE INSERTIONS...........................................10
CRISPR/CAS GENE REGULATION...........................................................................................................................11
Transcription repression...............................................................................................................................11
Transcription activation................................................................................................................................11
ADVANTAGES OF CRISPR/CAS 9 AS A GENOME-EDITING TOOL....................................................................................11

, CRISPR
Overview
Concept behind CRISPR/CAS:
- Part of the adaptive microbial immune system
- Clustered Regularly Interspaced Short Palindromic Repeats
- Family of DNA repeats found in:
o 90% of Archaea
o 40% of Bacteria
- Initially thought of as junk DNA
- Is a ‘memory of past genetic aggressions’
o i.e. showed what viruses and plasmids and phages the bacteria had been
exposed to in the past.
- Provides adaptive immunity – the removal/addition of CRISPR spacer sequences can
affect resistance to phage attack.

- CRISPR array associated with cas genes
- Array:
o Leader:
 AT rich
 Contains CRISPR promoter
o Spacers:
 Variable sequences of similar length
 17-100bp; 36bp average
o Repeats:
 Invariable sequence except the terminal repeat
 Partially palindromic
 23-50bp
 Forms stem loop

Features:
- Incorporation of Foreign DNA
o CRISPR/Cas system has ability to incorporate short sequences of foreign
DNA known as spacers
o Cas proteins incorporate new DNA by cutting it up and adding it to the
assay.
- Adaptive or Acquired Immunity
o Spacers transcribed into small non-coding RNAs (cRNA which is
complementary to incoming phage DNA) which in conjunction with Cas
protein complexes target and bind to incoming foreign DNA destroying it.
o Sequence-specific recognition process results in destruction of incoming
foreign DNA
- Heritable Immunity
o CRISPR/Cas system can readily acquire new spacers (or lose old ones)
which allows it to respond dynamically to a viral predator which evolves
at higher rates.

The benefits of buying summaries with Stuvia:

Guaranteed quality through customer reviews

Guaranteed quality through customer reviews

Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.

Quick and easy check-out

Quick and easy check-out

You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.

Focus on what matters

Focus on what matters

Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!

Frequently asked questions

What do I get when I buy this document?

You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.

Satisfaction guarantee: how does it work?

Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.

Who am I buying these notes from?

Stuvia is a marketplace, so you are not buying this document from us, but from seller mattclothier13. Stuvia facilitates payment to the seller.

Will I be stuck with a subscription?

No, you only buy these notes for $7.08. You're not tied to anything after your purchase.

Can Stuvia be trusted?

4.6 stars on Google & Trustpilot (+1000 reviews)

82215 documents were sold in the last 30 days

Founded in 2010, the go-to place to buy study notes for 14 years now

Start selling
$7.08
  • (0)
  Add to cart