Real Cats Wear Pink
Background: Scientists have mapped the brine-shrimp genome; these are the shrimp eaten by Flamingos. A gene in the brine shrimp causes the birds to turn pink. The color is from a type of carotenoid, a group of pigments also found in carrots and other organisms.
Goal: Students will simulate genetically modifying an organism to create a desired trait
Objectives: Students will
· Follow directions to perform a simulated genetic modification
Materials:
· Color picture of “Mr. Green Genes” the glow-in-the-dark cat
· Heat bath accessible to all groups
· Pink powdered paint, like Tempera
· 1 bottle corn syrup
· Ziplock baggie labeled “Biohazard Waste”
The following equipment will be needed for each lab group:
· 1 “bacteria” starter plate (this plate actually is just plain agar)
· 1 agar plate
· 3 small test tubes
One labeled “DNA Sample”
Another labeled “Transformation Solution”
The third labeled “Carotenoid Plasmid”
· 1 test tube stand
· 1 test tube clamp (optional: students can hold this with their hands as nothing toxic or dangerous is in any of the test tubes)
· 1 container with ice water
· 2 inoculation loops
· 2 pipettes
· Safety goggle and gloves for every student
· 1 timer
Time Required: 60 minute class period
Standards Met:
· Life Science Standards: Structure & function in living systems
· Science and Technology Standards: Understanding about science & technology
Procedure:
Prep:
You are simulating genetic material. Nothing in this lab is a biohazard or toxic.
1. Prepare the agar plates or purchase the agar plates
2. Label test tubes for each group of students (see materials)
3. Make the “Transformation Solution”
· Place water in each test tube labeled “Transformation Solution”
4. Make “Carotenoid Plasmid”
· Mix 1 cup of corn syrup with ¼ of water to create a solution that will have enough viscosity to adhere to the loop
5. Fill each “Carotenoid Plasmid” test tube with 25 ml of solution (about ¼ of the way full)
6. Make ice water baths for each group
7. Prepare heat bath to approximately 40 degrees C
8. After students have left the building, sprinkle their agar plates with pink powdered paint and reseal to simulate the carotenoid gene having been successfully implanted to the bacteria. Ha!
During Class:
· Show the students the Genetic Engineering Comic. Go through the questions on the sheet
· Show students the picture of “Mr. Green Genes”.
· Pairs of students should discuss how they think the scientists made a glow-in-the-dark cat.
· Tell students they are going to complete a similar process today: genetically modifying bacteria to turn pink by adding a gene with the pigment, carotenoid. This is the pigment that makes Flamingos turn pink because they eat brine shrimp containing this gene
· Show “Real Cats Wear Pink” ppt
· Give students the lab procedure sheet and walk them through the steps
Enrichment:
· Students can read “Mr. Green Genes” story
Real Cats Wear Pink: Genetic Engineering Comic Strip
What did the engineers do to the chicken?
Why did they want this outcome?
What did the genetic engineers have to do to create this chicken?
Do you think this genetically modified chicken is feasible?
Do you think this genetically modified chicken is ethical?
If you were able to make genetic changes to living organisms, what would you like to see?
Real Cats Wear Pink: Glow-in-the-dark cat a genetic success
How are pets genetically modified?
Transgenics:
a) For a specific breed, the genome is mapped and a trait (good or bad) is found. If the trait is undesirable and should be removed, the genotype responsible for the trait is found. Using the information from the genome sequencing, scientists determine in which breed the trait is not strong. The breeds without the undesirable traits are mated.
b) For a specific breed, the genome is mapped and a trait (good or bad) is found. The genotype is “knocked out” at the cellular level if the trait is one to be removed. A genotype can also be “knocked in” at the cellular level if the trait is one to be added.
Real Cats Wear Pink: Lab Procedure
1. Put on safety glasses and gloves
2. Gather materials:
· 1 “bacteria” starter plate
· 1 agar plate
· 3 small test tubes
1. One labeled “DNA Sample”
2. Another labeled “Transformation Solution”
3. The third labeled “Carotenoid Plasmid”
· 1 test tube stand
· 1 test tube clamp
· 1 ice bath
· 2 inoculation loops
· 2 pipettes
· 1 timer
3. Using a pipette, transfer 1ml of transformation solution to the tube labeled DNA sample.
4. Using the test tube clamp, one member of your group should bring the “DNA Sample Test Tube” to the warm water bath. Another group member should bring the timer.
5. Heat shock your “DNA Sample Test Tube” for exactly 50 seconds.
6. Using the test tube clamp, hold the “DNA Sample Test Tube” in the ice bath for 1 minute.
7. Transfer the bacteria from the agar plate to the “DNA Sample Test Tube.
· Use a sterile loop to pick up several colonies of bacteria from the starter plate. This can be done by dragging the loop across the plate so that it lightly scrapes the colonies off the surface. Transfer the bacteria to the “DNA Sample Test Tube” by spinning the loop rapidly after it is immersed in the liquid.
· Repeat this procedure 4 times. Each person in your group should transfer bacteria at least once!
8. Add the carotinoid plasmid to the “DNA Sample Test Tube”.
a. Get a new sterile loop.
b. Immerse the loop into the test tube containing “Carotinoid Plasma”.
c. When the center of the loop is coated with a film, transfer it the “DNA Sample Test Tube” – it should look like a bubble wand! (see picture)
d. Do this 2 times.
9. Using the test tube clamp, hold the “DNA Sample Test Tube” in the ice bath for 2 minutes.
10. Return to your station.
11. Transfer Bacteria to the Culture Plates
a. Immerse the loop into the “DNA Sample Test Tube”.
b. Gently spread the solution on the agar plate.
c. Repeat this procedure 3 more times.
12. Incubate the Plates by letting them sit at room temperature overnight.
13. Disposal and Clean-up
a. The used loops and pipettes should be disposed in a biohazard container. Ask your teacher where this is located in your classroom.
b. The agar plate containing bacteria that you used for your initial culture should also be disposed in a biohazard container.
c. Return the test tubes to the area designated by your teacher.
d. Your agar plate with the bacteria should be taken to the area designated for incubation by your teacher.
e. The surface of your work area should be sprayed with disinfectant and wiped down with paper towels.
Don't forget to wash your hands!
Draw and label what you think your agar plate will look like tomorrow:
Real Cats Wear Pink: Glow-in-the-dark cat a genetic success
Scientists use fluorescence as genetic marker, but do admit a fun factor
By JOHN POPE, Newhouse News Service,Wednesday, October 22, 2008
New Orleans — Everyone knows that cats can see in the dark, but that wasn’t good enough for some New Orleans scientists. They produced Mr. Green Genes, a cat that glows in the dark and is destined to be more than just a novelty for Halloween parties.
He’s a nearly 6-month-old orange tabby but, under ultraviolet light, his eyes, gums and tongue glow a vivid lime green, the result of a genetic experiment at the Audubon Center for Research of Endangered Species.
RUSTY COSTANZA/Newhouse News Service
Mr. Green Genes is the first fluorescent cat in the United States, said Betsy Dresser, the center’s director.
The researchers made him so they could learn whether a gene could be introduced harmlessly into the feline’s genetic sequence to create what is formally known as a transgenic cat. If so, it would be the first step in a process that could lead to the development of ways to combat diseases via gene therapy.
The gene, which was added to Mr. Green Genes’ DNA when he was created earlier this year in the Audubon center’s laboratory, has no effect on his health, Dresser said.
Cats are ideal for this project because their genetic makeup is similar to that of humans, said Dr. Martha Gomez, a veterinarian and staff scientist at the center.
Why a glowing cat?
To show that the gene went where it was supposed to go, the researchers settled on one that would glow.
The gene “is just a marker,” said Leslie Lyons, an assistant professor of population health and reproduction at the School of Veterinary Medicine at the University of California, Davis, who is familiar with the Audubon center’s work.
“The glowing part is the fun part,” she said.
Glowing creatures made international news earlier this month when the Nobel Prize in Chemistry was awarded to three scientists who had discovered the gene through their work with jellyfish. They used the gene, whose formal name is enhanced green fluorescence protein, to see how things work inside animals and even inside cells.
Mr. Green Genes — his name comes from Mr. Green Jeans, a character on the long-departed “Captain Kangaroo” television show — is deeply suspicious of strangers. He spends most of his days napping, and he doesn’t like being held when he doesn’t want to be cuddled.
In normal light, the 7-pound cat, who lives at the center, looks and acts like any other feline.
But turn out the room lights and switch on some black light, and you can see glowing ears, nostrils, eyes and gums. Those body parts light up because the protein is more likely to express itself in mucous membranes, Lyons said.
“You can’t lose that cat at night,” said C. Earle Pope, the center’s senior scientist.
“The frozen zoo”
In theory, his litter box could glow, too, because cat droppings include epithelial cells, where the gene can be found. But there is entirely too much other stuff around them to allow for readily visible glowing without messy lab work, Gomez said.
The Audubon center started its animal-cloning experiments in 2001. Two years later, Ditteaux, an African wildcat, was born there. He was the world’s first cloned wild carnivore.
Cloning starts with cells — generally skin cells, Gomez said, because retrieval isn’t too invasive — and the cells’ genetic material is stored in a tank of liquid nitrogen where the temperature is 316 degrees below zero. The Audubon center has 12 such tanks of genetic specimens awaiting use; Dresser calls them “the frozen zoo.”
For work with felines, eggs are collected from a donor cat — usually a domestic cat — and the DNA is removed and replaced. To create Mr. Green Genes, the fresh DNA included the fluorescent gene.
Then the fertilized egg is inserted into a surrogate mother cat for a pregnancy lasting 65 to 70 days.
After Ditteaux’s arrival, Gomez was invited to discuss it before a group of gene-therapy specialists, who, she said, were interested in the prospect of creating a genetic model for fighting diseases.
A tool to spot cystic-fibrosis
The Audubon scientists want to use their technique to develop a gene-therapy treatment for cystic fibrosis, an incurable hereditary disease for which, Gomez said, there are no gene-therapy models.
The fluorescence gene will go alongside the cystic-fibrosis gene and make it easy to spot. The long-term goal of this process, for which there is no timetable, is the production of what Gomez calls a “knockout gene.”
Work on this project is under way, she said. “We are getting some preliminary data, but we don’t have the full funds for it.”
Mr. Green Genes’ next role for the center will combine science and sex. He will become a stud so the Audubon team can determine whether the fluorescence gene can be transmitted. That should take no more than two breeding cycles, Gomez said.
“If he is fertile and if the female is fertile, it should be quick,” she said. “The idea is not to have a lot of green cats around, but to demonstrate that the gene can be passed.”
After that, he will retire to Gomez’s home, where two cats already live.
“I feel that he is my baby,” said Gomez, who led the team that created him.
“You have to realize that this is our first transgenic cat,” she said. “I don’t want him to go to just anybody. I feel he is mine.”
http://www.ajc.com/services/content/pets/stories/2008/10/22/glowing_cat_green_genes.html
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