Hess Associates

What is CRISPR-Cas9 and Gene Editing anyway?

The term CRISPR – Clustered Regularly Interspaced Short Palindromic Repeats – refers to the unique organization of short (partially palindromic) repeated DNA sequences found in the genomes of bacteria and other microorganisms. These sequences form a crucial component of their immune systems .

Scientists found that interspersed between the short DNA repeats of bacterial CRISPRs are similarly short variable sequences called spacers, derived from the DNA of viruses that have previously attacked the host bacterium. Whenever a virus invades, the bacteria takes a piece of it and adds it to the existing spacers, so effectively puts its sequence in a growing memory bank.

Double-stranded CRISPR repeats and spacers in the bacterial DNA undergo transcription, the process of copying DNA into single-stranded RNA molecules, which then circulate in the cell.

If a virus invades, and it has invaded before, these RNA memory strands (guideRNA or gRNA) will bind to the virus and direct the cell to destroy the virus by having the cell cut it up with a special enzyme called Cas9. Cas9 will be attracted to, guided to, the cutting site by the guide RNA. (see https://sitn.hms.harvard.edu/flash/2014/crispr-a-game-changing-genetic-engineering-technique/
for more detail and an excellent diagram).

CRISPR has applications in the food and dairy industries, preventing infection of crucial bacteria by viruses.

Scientists have adapted this technology to eukaryotic (plants and animal) cells, in order to carry out gene editing.
They use, therefore: Cas9 : an enzyme that cuts double stranded DNA at a specific place in the genome and gDNA: a predesigned 20 base long RNA strand (thus copying the spacer idea)
which binds to its complementary sequence in the genome, attracting Cas9, which then cuts the double-stranded DNA. As the cell prepares to repair the damaged DNA, scientists harness this DNA repair machinery to introduce changes in the gene. Essentially gene editing is a unique technology that enables geneticists and medical researchers to edit parts of the cellular DNA by removing, adding or altering sections of its sequence.

Going forward, the use of CRISPR technology and gene editing in medicine is only in its infancy.

Recently this technology has been the subject of a contentious law suit between the Broad Institute (Harvard) and UC Berkeley (details (https://www.statnews.com/2017/02/15/crispr-patent-ruling/).


The Origin of Labour Day Do You Offer Your Employees a Long Enough Vacation Package? Using Work Issued Cell Phones The “Heir” and the “Spare” in Business Job Hopping Prospectives and Perspectives Your Company’s Strength is its People – Wherever They Work Salary Transparency in Job Posts – It’s on its Way Haunted by Ghosting? How to Slowly Move People Back to the Workplace What’s the New Deal with Blue Glasses Frames? Any Relationship to Job Interviews? How Hiring Managers are Using Social Media to “Vet” Potential Candidates Tips on Conducting Video Interviews with Candidates What Does Your Job Title Mean to You? A Job Seniors Can Bank On Why You Should Hire an Overqualified Person Does a Vacation Make You More Productive? Dress for Success While You #PressforSuccess What a Difference a Class Makes Before You Send a Resume, Do These Things Why it Makes Sense to Give Your Staff an XMas to New Year’s Break Women in the Male Dominated Workplace: Plight and Progress When Does Using a 3rd Party Recruiter Save You Time & Money? What is Corporate Cultural Fit? Why Hire a Recruiter on an Exclusive Basis? Should a Man Wear Brown Shoes to an Interview? Why is Retirement so Challenging? When is it time to look for a new job? Getting over the Sluggish Blues What is CRISPR-Cas9 and Gene Editing anyway? Dating and Your Workplace – Do or Don’t – But Most Do 10 Ways to Work from Home Efficiently How do Deal with Annoying People at Work Is a Manager Entitled to Overtime Pay in Ontario? What are the Disadvantages of Hiring Contract vs Full-Time? Mind the Gap!!! And How to “de-Gap” your Resume How to Hire the Best Talent 5 Reasons to Hire a Consultant The “Pink Collar” Man in the Glass Elevator How do You Find a Summer Job in Ontario? How to Keep Employees Happy and Motivated Who or What is Generation Z? How to Annoy your Recruiter Should Candidates Ask Questions During an Interview? Rearing the “All Digital Generation”? Is the traditional resume disappearing? No Future for Voicemail on Land Lines Online Programmatic Advertising The Internet of Things Working for a Younger Boss Stephen Poloz and Working for Free How Important Are Reference Letters? Psychological Health and Safety in the Workplace Ideas on Changing Careers Back To The Future 10 Telephone Interview Tips On Edward Snowden and Privacy Issues The Second Most Important Issue Facing a Small Company What is Bitcoin – What Are Bitcoins? The Dollar Cost of Employee Turnover Five Most Important Reasons a Company Should Hire Contract Staff Use of Contract Workers in the Biopharmaceutical Industry Metadata Monsters Toronto HotDocs Exposé of the Dangers of the Internet