Purdue University 's Richard Vierling is preparing to have his successful soybean DNA transplant experiments recreated on board a NASA space shuttle scheduled for launch April 13. Vierling's first microgravity experiments were conducted in late 1998 by the oldest man to ever fly in space, former astronaut and U.S. Senator John Glenn.

Those experiments, which tested whether DNA transfer could be conducted in microgravity, proved not only that it could be done, but also that it was more successful and efficient than DNA transfers in a control group here on earth.

Of the soybean seedlings from the first space experiment, 9 percent exhibited the trait introduced. On earth, less than 1 percent of the control group showed the trait. "The rate of transient expression in a space environment was more than tenfold over the success rate of a comparable terrestrial experiment," Vierling says.

Those experiments seem to indicate that space may be a better environment for conducting gene transfers. "Genes were transferred more efficiently to targeted cells in space than on earth. The results were so significant, we're going to improve our experiments and try them again," he says.

Vierling, an adjunct associate professor of agronomy, is also director of the Indiana Crop Improvement genetics program. He is working on this project in conjunction with Stephen Goldman, a professor of biology at the University of Toledo. Their initial success was reported in the January 2000 edition of the journal Chemical Innovation produced by the American Chemical Society.

Vierling says despite modern advances in biotechnology, genetic engineering is still a very inexact science. "Some plant species are easier to work with than others," he says. "Soybeans in particular are very inefficient to work with, and we're hoping to learn through these experiments ways that we can improve our odds of success even here on earth."

The first space mission involved about 1,000 soybeans in what Vierling describes as "a crude experiment." "We didn't even know if you could do gene transfer in space," he says. "Some people had told us that it wouldn't be possible."

He says some of the initial misgivings centered around the fact that the bacteria used to transfer the DNA must be mobile. "They have to 'swim' in a solution, and liquids are hard to control in zero gravity. You must keep the liquid in contact with the cells to be successful," Vierling says.

However, the "floating" effect of space may be a benefit in this case, a hypothesis they hope to explore in this next round of experiments. Vierling already has applied for a patent based on the initial experiment results.

Vierling says commercial genetic transformation and regeneration of whole plants now is limited by the the low success rates. "We hope to learn what makes space a more efficient environment for these experiments and then design equipment for use on earth to increase our efficiencies here," he says.

The Purdue soybeans will have another Purdue Boilermaker connection while on board the space shuttle Atlantis this spring. Payload specialist Mary Ellen Webber, a Purdue chemical engineering graduate, will be among the crew at liftoff scheduled for 8:41 p.m. April 13.