For more information, contact George Stamatis, 216-368-3635 or gxs18@po.cwru.edu.

Posted 12-20-99

Zebrafish may hold key to celestial human reproduction

What do we have in common with zebrafish? According to Stephen Moorman, an assistant professor of anatomy who directs zebrafish research at Case Western Reserve University's School of Medicine, the silvery striped fish have a vestibular system similar to ours.

Stephen Moorman, assistant professor of anatomy, CWRU's School of Medicine

The human vestibular system is in the inner ear and helps coordinate balance and equilibrium. It relies on gravity to tell the body which way is up.

However, in space, there is no gravity, so would the vestibular system develop normally in humans or zebrafish raised in space? Moorman's research aims to answer that question.

To do this, Moorman deprives his test subjects, zebrafish eggs, of gravity using a micro-gravity system that NASA developed for growing cell cultures.

Two years ago, while working at the University of Northern Texas Health Science Center, Moorman and summer students from a local high school discovered that they could use NASA's Rotating Wall Perfused Vessel to create a micro-gravity environment for fish eggs. Moorman put zebrafish eggs in the vessel for three days at which time the fish were considered fully developed. What he found surprised him.

With gravity removed, the fish relied on light to orient themselves. If the light was shone through the bottom of the tank, the zebrafish would float belly-up, thinking the light should be above them. Normally, the fish wouldn't fall for this.

"If they're in normal room light they're fine," Moorman said, "but they get disoriented if the lights are off or somewhere else."

Moorman's research is of great interest to NASA because it implies that the same results may appear in humans. Always looking to the future, NASA will use Moorman's results to plan possible colonies in space.

"If a woman carries a baby in space, the question is whether the fetus will develop normally in an environment with no gravity," said Moorman. "Will the mother need to return to earth for the fetus to have gravity, or will space stations need centrifuges to create gravity for the mother? These are the types of questions that need to be answered if colonization in space is ever to be considered."

So before colonies of humans are created in space, zebrafish will lead the way. According to Moorman, zebrafish will be reproducing on board the space station, which is currently under construction, long before mice or rats will.

For more information, see Moorman's Web site, http://mediswww.cwru.edu/dept/anatomy/moorman/Default.htm.

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