Sources: Kendra Miller, mkendra@k-state.edu;
Raven Skinner, rskinner@k-state.edu;
and Sunish Sehgal, 785-532-1353, sksehgal@k-state.edu
Photos available. Contact media@k-state.edu or 785-532-6415.
News release prepared by: Kristin Hodges, 785-532-6415, khodges2@k-state.edu

Monday, Oct. 19, 2009

K-STATE STUDENTS HELP CREATE MAPS OF WHEAT CHROMOSOMES TO IMPROVE VARIETIES OF THE CROP THAT CAN FEED MORE PEOPLE AND GROW IN HARSH CLIMATES

MANHATTAN -- Kansas State University undergraduate students are conducting research to help map wheat chromosomes for a project that could help the crop feed more people and grow in harsh climates.

The students are working in K-State's Wheat Genetic and Genomic Resources Center with Sunish K. Sehgal, research associate in plant pathology. The students are: Kendra Miller, junior in biology and premedicine, 2007 graduate of Republic County High School, Belleville; and Raven Skinner, sophomore in biology and premedicine and 2008 graduate of Paola High School.

"The projects that we are working on in the lab are huge -- some of the largest being attempted worldwide," Miller said. "The wheat genome is several times the size of the human genome, so that puts it into perspective."

Miller and Skinner are involved in a project to create a physical map of four chromosomes of wheat. A physical map of a chromosome is a physical representation of the linear order of genes and other landmarks along the chromosome. Sehgal said mapping wheat genomes is complex because wheat has a large amount of DNA in its nucleus, and the nucleus contains three different genomes.

To construct a physical map for wheat, the researchers are using a chromosome-by-chromosome approach, where chromosomes or chromosome arms are separated by the flow cytometry technique, Sehgal said. Then genomic DNA from each chromosome or chromosome arm is fragmented and cloned. Each clone is fingerprinted, and the data are analyzed to develop a fingerprint map.

"Kendra and Raven form an excellent team," Sehgal said. "One develops the map and the other anchors the map with markers for defining the orientation and comparative genomics with other crops like rice and corn."

Miller's role in the project involves inoculating bacteria with DNA that the lab researchers want to analyze. Then she isolates the DNA, which is then digested by enzymes and labeled with fluorescent dyes. Later it's put into a DNA sequencing machine, which is where a fingerprint map of each individual chromosome is developed.

Skinner's role in the project involves the physical anchoring of markers on the cloned DNA segments. She also recently began replicating bacterial artificial chromosomes to show where specific clones are located in the wheat genome.

Sehgal said physical maps are important for advances in wheat genetics and genomics because they are the first step in sequencing the entirety of the complex wheat genome. The maps demonstrate that large genomes like wheat can be sequenced chromosome by chromosome. This work is essential for understanding and manipulating the genetics of wheat for enhanced yield potential, resistance to pests and diseases, and tolerance of adverse environmental conditions. That means sustained development of better wheat varieties.

"Mapping and sequencing the wheat genome will allow us to start looking at how we can feed more people with a larger yield or how we can grow wheat in climates unsuited for vegetation," Skinner said.

Skinner became involved with the research as a freshman at K-State. She said it wasn't difficult to find an on-campus research job. She visited K-State's Career and Employment Services and learned about the lab assistant opportunity. Skinner began her research experience by learning basic lab techniques like how to extract DNA from plant tissue.

"I will be applying to medical school at the end of my junior year, and I think having a research job that involves mapping out a genome my first year in college will show how much I have to offer," Skinner said. "I've had the opportunity, which a lot of graduate students don't get, to work on a project that is worldwide and that will affect millions in the future."

Miller also will apply to medical school. She said she wanted to work in a lab as an undergraduate to gain experience.

"I love to be able to put a reason and an actual process behind the things I learn in textbooks, and here I am able to do that every day," she said.

Two more students have recently started working with Sehgal on the physical mapping project: Aaron Avery, junior in biology, chemistry and predentistry and a 2006 Manhattan High School graduate; and Jayce Brandt, sophomore in agronomy and a 2008 Paola High School graduate.

The projects are under the leadership of K-State's Bikram S. Gill, University Distinguished Professor of plant pathology. The research is funded by a $1.5 million grant from the National Science Foundation. Funding also is provided through a $1 million grant from the National Research Initiative of the U.S. Department of Agriculture's National Institute of Food and Agriculture, which supports a collaboration between K-State and researchers at the U.S. Department of Agriculture in Fargo, N.D., and at South Dakota State University.