• Describe CRISPR’s role as a tool in modern genetics.
• Identify and describe the function of the RNA guide molecules, genomic DNA sequences, DNA repair sequences and the Cas9 molecule within the CRISPR process.
• Differentiate between diseases that may be impacted by CRISPR and those less likely to benefit.

In this lesson, students will learn about clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated proteins (Cas), including Cas9. Students will explore how CRISPR technology and Cas9 proteins can target and change base pairs of DNA. Students will be introduced to genetic disorders and learn how CRISPR technology can be used during treatment.

Teacher Preparation

• Print out one Intro to CRISPR Lab Notebook per student. This document can be printed double-sided.
• Print one CRISPR Activity per student. This document should be printed single-sided because students need to cut out some pages.
• Each student will need scissors, clear tape and highlighters.

Vocabulary

• CRISPR-Cas9
• Non-homologous end joining (NHEJ)
• Homology-directed repair (HDR)
• DNA
• RNA
• Protein
• Central dogma of biology

Lesson

Follow the Intro to CRISPR Slideshow.

Slide 1
Explain that:

• CRISPR is a tool for genetic modification.
• To understand genetic modification, students will need to:
  • Remember the central dogma of biology, which will be reviewed in this lesson.
  • Learn current information about genetic disease.

Slide 2
Play the video Genome Editing with CRISPR-Cas9.

Slide 3
Ask students to fill out the know and want to know sections of the KWL chart in their lab notebook.

After giving your students time to write about what they know and want to know about CRISPR, have them share with a table partner or lead a classroom discussion about what they wrote.

Slide 4
Explain what we should know so far:

• Your genome is the instruction manual that makes you, YOU.
• CRISPR is a tool for finding and replacing pieces in your genome.
• CRISPR is to a genome as control F is to a computer.

Slide 5
Ask students to write a short paragraph to collect their thoughts about DNA, RNA and protein’s relationship in the cell.

This relationship is referred to as the central dogma of biology. If your students are having trouble remembering how DNA works in the cell or you have not approached this topic yet, use the DNA to Protein Lesson Plan.

Slide 6
Tell students:

• Your paragraph might look like the example on the slide.
• The main points are:
  • DNA’s code is changed to RNA.
  • RNA is changed into amino acids that – when correctly strung together and folded – make up protein.

Slide 7-9
Discuss the central dogma of biology: DNA is transcribed into RNA, which is translated into protein.

Slide 10
Ask students to complete the exercise on page two of the lab notebook.

For each of the four tables, transcribe and translate the sequences. The first table has no mutations and the following three tables each introduce a specific type of mutation.

Make sure the students can transcribe the DNA into mRNA. Use the table on slide 10 to translate the amino acid chain. You can also print the table. After filling out the tables, answer the questions in the lab notebook.

Slide 11
Ask students to finish the genetic disease definition in their lab notebook.

Slide 12
Show the video How This Disease Changes the Shape of Your Cells.

Ask the students to answer the questions related to the video in their lab notebook. The first three questions ask them to answer questions while watching the video and the second three questions ask them to think about genetic modification.

Slide 13
Discuss these questions from their lab notebook:

• Is it time to start curing diseases using gene-editing tools like CRISPR?
• What is the problem that CRISPR could solve in sickle cell anemia?
• The genetic change that causes sickle cell anemia is a substitution. The substitution changes a T to an A in the gene that codes hemoglobin beta. CRISPR is a gene-editing tool that allows scientists or doctors to make changes in specific places in a genome. The video showed that the same mutation that causes sickle cell disease also protects a person from malaria. Do you think the gene causing sickle cell disease should be edited? Why?

This would be a good time to make sure students understand genetic diseases. In addition, check for any experts on genetic diseases in the class. You may have a student who is excited to share something about cystic fibrosis or Down syndrome because they know someone affected. Many rare diseases also fall in the genetic diseases category.

These discussions may spark an interest in some students. One place to learn more could be the Coordination of Rare Diseases at Sanford (CoRDS) rare disease registry. This database is helping advance the research of over 7,000 rare diseases. You can find links to several high-quality sites related to rare diseases at the bottom of the CoRDS homepage in the Meet Our Partners section.

Slides 14-17
Discuss some categories that genetic diseases may fit. These slides identify how genetic diseases can vary.

Slide 18
Have students record in their lab notebooks that not all disorders cause disease.

Slide 19-20
The slide shows that mutations cause disorders. Some disorders can be classified as diseases. The examples presented are primary ciliary dyskinesia (PCD) and situs inversus (SI) – a disease and disorder, respectively.

People affected by PCD have cilia that don’t move correctly, which can cause a variety of problems. Doctors usually diagnose this disease based on respiratory problems.

SI is a disorder caused by mutations in the same gene but different nucleotides. SI causes organs in your body to be mirrored, which means they’re reflected on the opposite side of the body. The mirrored organs often function normally. The disorder can go undetected until a medical test, autopsy, surgery or X-ray reveals the patient’s anatomy.

Slide 21-25
Discuss the four distinct types of genetic disorders.

Ask students to write each type of genetic disorder in their lab notebook:

• Single gene inheritance: Only a single gene has mutations. Often, as in sickle cell anemia, it is a change of a single base pair. Other diseases, like Huntington’s disease, may be caused by having more copies of a specific region of their DNA.
• Multifactorial genetic inheritance: These diseases have genes located in many spots throughout the genome.
• Chromosomal abnormalities: There are missing or additional chromosomes, most commonly the result of incorrect cellular divisions in meiosis.
• Mitochondrial genetic inheritance: The mitochondria contain tiny amounts of DNA that code for genes specific to the mitochondria’s function. If changes occur in these genes, they will be passed down from the mother to her children and daughters can pass them on to their children. These diseases are usually rare because mitochondria are important to the function of the cell and the organism.

Note: CRISPR is a technology that lets scientists change a small number of base pairs within a cell. With our current understanding of its uses, scientists can’t use CRISPR to cure a disease that results from changing an entire chromosome.

Slide 26
Give students a recap of the topics they’ve explored in this lesson.

Slide 27
Note: Here, the presentation transitions into CRISPR and Cas9. Slide 37 introduces the CRISPR Activity, but you can also introduce the activity here and start the cutting part of the activity depending on how much time you have.

Slide 28
For the rest of the lesson, students will learn more about CRISPR. Remind students that CRISPR is a tool for finding and replacing pieces in your genome.

Slide 29-30
Lead a discussion about CRISPR with these questions:

• What does it mean to be a genome-editing tool?
• If a genetic disease can be caused by a genetic disorder, can CRISPR just reorder the genome as we might bring order to a messy room?
• How does CRISPR sweep away genetic disorders?

Slide 31
Explain that:

• CRISPR is an acronym for clustered regular interspaced short palindromic repeats. Have students fill this in on their lab notebooks.
• Scientists found these repeats in the DNA of bacteria.
• Scientists investigated these repeats further and found them to be part of a bacterial immune system.
  • When microbiologists refer to CRISPR, they are talking about a portion of the bacterial genome (DNA).
  • When other scientists talk about CRISPR, they’re usually talking about the CRISPR-Cas9 system, which is what this lesson focuses on.
  • The CRISPR-Cas9 system uses a specific CRISPR-associated protein (Cas) to edit specific spaces in a genome. This edit can be carefully controlled by the Cas protein that scientists select.

This analogy may help students think about CRISPR’s relationship with the Cas proteins. CRISPR is like a bookshelf. It’s a place where information is stored. The CRISPR-associated proteins (Cas) are like the librarians. They place the books on the shelves. They find the books on the shelves and take the information from the books out to visitors.

Slide 32
For scientists to use CRISPR, they need to know the genetic sequence of an organism. These slides use the word mutation, and you could steer the kids to think about the genetic disorders that you have discussed with them.

Explain that once scientists know which part of the DNA they want to change, they need to create some RNA that will help them find the right section of DNA within a cell. This piece of RNA is called guide RNA.

Slide 33
When scientists know their target sequence, they need to choose the correct Cas protein. The Cas proteins have many functions, as shown on the slide. The function scientists are most interested in is the fourth function. The Cas protein will destroy the viral DNA by cutting both strands of the DNA sugar-phosphate backbone. In your cells, there are repair mechanisms that let your body fix your DNA. There is no repair function that will do this for the viral DNA in bacterial cells.

There are more than 40 identified Cas proteins. This lesson focuses on Cas9, one type of Cas protein.

Slide 34-35
Explain that:

• The Cas9 protein is like a pair of scissors.
• Scissors can bring order to things like long string or long hair.
• Cas9 can sometimes help bring order to genetic disorders.

Ask students to record this in their lab notebooks.

Slide 36
Ask students to read the numbered bullets on the slide.

The numbered bullets take the students through the CRISPR process from the mutated DNA to the action of DNA cleavage. The cleavage is the most important part of the CRISPR process for doctors or scientists to change genes in non-bacterial cells. There is only one small step after this process, which involves DNA repair. Students will learn about DNA repair in the hands-on activity.

Slide 37
Introduce the CRISPR Activity. This activity will take around 40 minutes. Students will work in pairs.

Ask students to follow the activity to:

• Produce strands of DNA, RNA and the Cas9 molecule.
• Make specific cuts identified by where the RNA matches with the DNA.
• Go through the DNA repair process in the cell.

Follow the activity systematically to work through the Cas9 protein cutting the DNA and the repair process. Then, answer the questions at the end of the activity.

Watch our CRISPR Activity tutorial for guidance through the CRISPR activity.

Slide 38
Watch the video How Gene Editing is Curing Disease. Tell students that they will need to defend the following claim after the video: People with sickle cell disease would benefit from CRISPR technology. Use evidence from the lesson in your answer.

In this video, students will be introduced to a patient going through the process of using CRISPR technology to cure sickle cell disease. Students should be familiar with sickle cell disease from the previous video.

Slide 39
After they’re done, explain that:

• CRISPR has some ethical concerns with its use, such as the ethical concerns related to sickle cell disease and malaria.
• There are many applications of the CRISPR system to help scientists better understand the human body.
• This slide highlights research that uses CRISPR to better understand brain development. Learn more about the Pilaz Lab.

Slide 40
Ask students to complete any remaining sections in their lab notebooks. Discuss what students still want to know about CRISPR.

This lesson just scratches the surface of how CRISPR is currently being used. The 2020 Nobel Prize in chemistry was awarded to the scientists Jennifer Doudna and Emmanuelle Charpentier for the development of a method for genome editing. Encourage students to look for CRISPR in the news and share how it’s currently being used.

Finally, go back to the KWL chart and identify what the students learned and what they still want to learn about CRISPR. When finished, students should be able to:

• Describe what CRISPR stands for.
• Know that Cas proteins make cuts in DNA.
• Understand that cellular repair machinery makes changes happen at cut sites.
• Describe how changes to DNA can shut off certain genes.
• Describe how the CRISPR and Cas 9 system can make lasting changes for people with genetic disorders.

Extend the Lesson

Use this video about CRISPR technology in livestock to extend the lesson.

Sanford Connection

Pilaz Lab

CRISPR-based gene therapy is a powerful tool for making specific changes to a genome. In human bodies, scientists are just beginning to scratch the surface of possibilities with diseases like sickle cell disease and Leber congenital amaurosis.

Sanford Research has dedicated resources to create and retain experts in molecular biology, including in the use of CRISPR-Cas9 mediated genome editing. These experts help remove barriers that new scientists may experience to using the CRISPR system, and they help scientists bring new techniques into the fold. The applications in the lab for these techniques are endless. Sanford Research is currently working on a variety of applications, including diabetes and kidney disease.

Learn more about molecular biology at Sanford Research.

Did you try this lesson? Tell us about your experience.

View Survey