NEWS 498 “Genetic Engineering” from 04/26/10 e-mail, READY TO EDIT
Brief 5 Revised
You’re a developed blueprint. So is every other living organism. All organisms’ function and
appearance is determined by pieces of information called genes that are combined into a blueprint
called DNA. Genetically modified organisms (GMOs) occur when genes from two organisms mix to make
a new organism that often has better traits than the originals. According to the article, “Introduction to
Genetic Modification,” genetic modification has been around for thousands of years.
GMOs can be made in two ways. Traditional breeding is the oldest method. Many INTSORMIL
scientists use traditional breeding methods to develop better sorghum and millet. By selectively
breeding one plant with another, scientists develop hybrid offspring that combine desired traits. In
“Introduction to Genetic Modification,” Peggy Lemaux, director of the University of California Division of
Agriculture and Natural Resources Biotechnology Workgroup wrote, “Virtually every food in today’s
market has been modified in this way.”
Genetic engineering (GE) is also a form of genetic modification. GE allows genes to be
transferred between both the same and different species. Much of the controversy about GMOs is
actually about this method and the safety of resulting offspring.
Scientists who use GE choose the particular gene (piece of DNA that codes for a trait like
drought resistance) they want to exist in the new organism, cut it out of the donor organism’s DNA and
paste it into the new organism’s DNA. However, this process isn’t like the cutting and pasting kids do in
elementary school. DNA is 1/20,000th the width of a human hair.
Scientists usually perform GE in one of two ways.
• The first method involves a tiny soil organism called Agrobacterium. Scientists put the genes
they want the plant to acquire into the DNA of the Agrobacterium and let it do the work. The
Agrobacterium enters a plant and integrates its own genes into the plant’s chromosomes (the
part of the plant that holds the DNA), creating a modified cell within the plant.
• The bullet method uses micrometer-sized bullets coated with DNA. A special device uses a
change in helium pressure to shoot the bullets into the plant’s chromosome.
Once the new DNA is inserted into the chromosome, scientists manipulate growth hormones to
encourage the plant to grow more of the modified cells. With enough work and patience, scientists can
grow a plant made entirely of modified or engineered cells.
Though some INTSORMIL scientists work to identify and locate particular genes for particular
traits, INTSORMIL only uses traditional breeding methods to develop new varieties sorghum and millet
“We have what I would call biotechnology, but not the kind that takes genes from one specie
and puts it into another,” said John Yohe, INTSORMIL’s program director.
Yohe said because of the nature of the programs in Africa, and INTSORMIL and USAID’s focus on
extension activities that help get information to small farmers in the field, it’s likely that INTSORMIL
would retain the traditional breeding methods instead of using GE.
Lemaux, Peggy. “Introduction to Genetic Modification.” Agricultural Biotechnology in California Series.
Pub. 8178. July 2005. http://ucanr.org/freepubs/docs/8178.pdf
“Plant Genetic Engineering: Methodology.” Arizona State University Center for Bioenergy and
Photosynthesis. Oct. 2006.
“Exploring the Nanoworld: Size and Scale.” University of Wisconsin, Madison Materials Research
Science and Engineering Center. http://www.mrsec.wisc.edu/Edetc/nanoscale/index.html