Plant scientists and biology teacher bring molecular genetics and

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Plant scientists and biology teacher bring molecular genetics and
biotechnology to high school students
By Kim Colavito Markesich
Professor of Plant Science Gerry Berkowitz is working on two integrated projects that
bring cutting edge science to high school students.
In the first of the two projects, Berkowitz is working with future high school biology
teachers in the Teacher Education Program at the Neag School of Education. The
program is supported by a $30,000 component of Berkowitz’s current National Science
Foundation grant. Berkowitz and his postdoctoral fellow Rashid Ali created a two-week
intensive training program in molecular genetics for the Neag students.
The program began last summer when ten Neag students worked with Berkowitz and Ali
in their plant biotechnology laboratory. The students were paid a $1,000 stipend for the
two-week session and received hands-on training in DNA manipulation.
In the second project, funded by a $40,000 USDA Challenge Grant, Berkowitz is
collaborating with E.O. Smith High School biology teacher Jon Swanson. The two have
developed a molecular biology experiential learning program.
“Part of the reason I wanted to do this project is that I felt that the traditional way DNA is
taught in a high school class makes it difficult to understand,” says Swanson. “I wanted a
more hands-on approach.
”The program is composed of six lab modules, in which students write to a “fictitious”
Dr. Berkowitz as they unravel a DNA-based plant mystery.
The students begin by identifying the common research plant Arabidopsis. They compare
a wild-type (normal) plant with a sick (mutant) plant. In a series of letters to Dr.
Berkowitz, the students must determine why the plant is growing poorly. Dr. Berkowitz
first suggests they look at one particular gene.
Students extract the DNA, use a PCR machine to make copies of the gene, and then run
gel electrophoresis to visualize their products. It is established that the wild-type plant has
a functional copy of the gene, and the sick plant does not.
Now the students need to find out the missing gene’s function. They insert the gene from
both the wild plant and sick plant into yeast cells and grow them in a medium. Another
letter from Dr. B suggests that potassium might be part of the puzzle.
The students test different potassium levels, and find that the yeast with the sick (mutant)
plant’s DNA does not grow well in low levels of potassium. The yeast with the wild-type
plant’s DNA grows fine in low levels of potassium. The students discover that the
missing gene in the wild-type plant works as a channel to pull potassium into the cells.
“It introduces the concept of transgenic organisms. The yeast cells contain yeast DNA
and plant DNA,” Swanson says. The students see that genes are pieces of DNA that code
for certain proteins regardless of where they are placed.
Another lab module demonstrates the concept of proteomics, or the study of protein
shapes. Students learn how a protein’s function is related to its three-dimensional shape
and that the shape can be influenced by mutations in the gene encoding the protein. The
students participate in a lab session where they fold origami cranes to simulate the
folding of proteins. Half the class is given instructions that are missing a step. These
students are unable to assemble the crane. Swanson utilizes 3D modeling software to
show students the shape of the actual protein that makes the channel. If one amino acid is
altered, it changes the shape of the channel, adversely affecting protein function.
“The students absolutely love this,” Swanson says. “The equipment alone was enough to
hook the kids. They get a much better understanding because they applied it, rather than
just memorizing information.”
“I believe there are very few programs to teach molecular biology that take an integrated,
experiential approach,” Berkowitz says. “Students have the unique opportunity to take a
ride on the molecular biology information ‘superhighway,’ linking gene sequence to
protein structure, to protein function in a cell, and finally to the role of the gene in a
plant.”
“The students not only handle the information, they did a fantastic job,” Berkowitz says.
“Jon deserves a tremendous amount of credit. He translated what we wanted to do into an
actual program.”
The final piece of the project is the development of a training program for other teachers
that includes workshops, a Web site, and a support network for high school biology
instructors.
Terms
PCR: Polymerase chain reaction, a process used to amplify DNA.
Gel electrophoresis: An electric current used to separate out DNA molecules in a gel;
then a stain is used to visualize the DNA.
Transgenic organisms: Organisms containing DNA from more than one species.
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