A worm is more like a human than previous...( be grown on a single Petri dish in a f...)

The recently mapped human genome revealed that humans have only approximately 35,000 genes, whereas C. elegans has over 19,000 -- not a huge difference, according to Rothman, who said most scientists were startled to learn that humans did not have many more genes.

The similarities between the number and identity of genes in humans and worms allow researchers to extrapolate from worms to humans in their genetic research. He explained that the "gene knockout" technique that is used to learn about how single genes work can take a year or more to complete using mice.

In contrast, a revolutionary technique invented a few years ago allows worm genes to be knocked out literally overnight, thus speeding up gene studies enormously. ("Knockout" is the way that biologists study the function of genes by removing them one at a time, and examining the outcome.)

The initial experiment that led to the discoveries described in this cover article in Molecular Cell took only one day to complete. "We are learning about genetic switches and how they work together to create us," said Rothman. He said they are doing a systematic gene by gene removal to ask how the overall system works.

"It is analogous to learning about how a car works by removing its individual parts and asking what goes wrong when that part is missing," he explained. "This is teaching us an enormous amount about animal biology and ultimately human biology."

Rothman believes that the research into these genetic switches will provide a basis for tissue engineering, which will come to fruition in the next few decades. Replacement organs such as hearts and liver may eventually be grown in the lab, starting with a small amount of tissue from the person needing the new organ.

"As we learn what the switches are, for example what tells the embryonic cells to specialize into a heart, it will ultimately become possible to
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Contact: Gail Brown
gbrown@instadv.ucsb.edu
805-893-7220
University of California, Santa Barbara - Engineering
29-Mar-2001