Fruit Fly DNA May Unveil Cures
for Human Afflictions

12:12 AM EST; March 24, 2000; Atlanta, GA (CNN) -- A lowly fruit fly has given up all its genetic secrets to scientists who believe the insect's DNA map will aid in research of various human diseases and birth defects. The tiny fly bearing the scientific name Drosophila is an open book now that scientists have decoded its entire genetic blueprint -- or genome -- one chemical at a time.

"It's a very exciting time. The Drosophila genome plays such a key part in science," said Craig Venter of Celera Genomics, where much of the genetic research was done.

Insect Has about 13,000 Genes

Even though the fruit fly has only about 13,000 genes, compared to the [80,000 - 100,000] genes found in humans -- we're more similar to fruit flies than we might imagine. Seventy percent of the genes found in the flies are also present in humans. And because fruit flies reproduce and grow quickly, they are a scientist's dream laboratory specimen.

"There's literally hundreds to thousands of discoveries in the fruit fly that have helped us understand our own biology better," Venter said. "One is a set of genes that determine body segments in insects -- turns out those same genes control our body development as humans." And don't mock the tiny brain of the insect. "The key discoveries for understanding the molecular basis for how the human brain functions have come from the fruit fly," Venter said.

New Method for Gene Sequencing

Now researchers will have easy access to all the genes because scientists at Celera Genomics developed a new method to sequence vast amounts of genetic information. The "shotgun" method involves several intermediate steps:

• First, carefully remove the DNA from the nucleus of a cell;
• Next, break up the DNA randomly into very small segments (with overlapping ends);
• Then, analyze the pieces, one molecule at a time but in a parallel fashion;
• Then, use an expensive Super Computer to reassemble the genome, like a gigantic, linear jigsaw puzzle; and
• Finally, guess how certain known lengthy repeat units might go together, especially in the neighborhood of the centromeres or the telomeric caps at the centers or the ends, respectively, of the chromosmes. Note: highly repetitive sequences are not easy to reassemble using this method.

"By understanding those genes, by seeing what you can do in a fruit fly -- change the temperature, expose it to different chemicals -- and then knowing exactly what the fruit fly genes are, we'll learn something about why, sadly, things sometimes go astray in human development," said Prof. Arthur Caplan, a bioethicist at the University of Pennsylvania.

Although Celera is a private, for profit company, it plans to share its findings with researchers all around the world. [Editor's Note: Celera may not share its findings publicly for the human genome sequence until its financial partners have had an opportunity to determine the value of this intellectual property for their respective companies and associated patents have been filed. Nevertheless, this should not slow down the disclosure process for more than a year or so. Of course, the NIH Human Genome Project will be publishing its data in draft form immediately following verification of its accuracy.]

[Editor's Note 2: In the sense of manipulating genes or not, there is nothing particularly sacred about the individual genes that go into a species' genome. Natural selection (through a process of random mutations) would never hesitate to assign a value of "zero" to a gene that didn't help an organism become more competitive in its never-ending quest to leave behind strong offspring (the Biblical prime directive to go forth and multiply) in a variably hostile environment (one filled with relentless predators). But that wouldn't mean that such a valueless gene would be instantly deleted from the sequence. In might just be "covered up" in some way -- maybe waiting in the wings until it might again become useful in a different sort of environment. In fact, such "vestigial" genes (experiments that temporarily failed) might be left behind with no particular incentive to "clean up" the genome or strip out useless so-called "junk" DNA. Indeed, the phrase "ontogeny recapitulates phylogeny" [referring to the idea that mammals go through a "gill phase" of embryogenesis, harkening back to a time when we were all fish, I suppose] means that there must be a lot of "useless" DNA still hanging around in every single cell of our bodies. What if these genes for "phylogenetic embryogenesis" could be deleted from all of our cells by deliberate excision, including from our germ cells? Assuming this were not an unexpected "show stopper" in terms of normal embryogenesis, would that have any impact on our species? I don't think so. And what if -- in a post-reproductive adult -- we were hypothetically to delete from every cell (by some means of genetic engineering not yet defined) all the genes that had to do with embryogenesis? Would that have any impact on the individual? Of course not. Accelerating the rate of mutation from one of pure randomness (a stochastic process) to one of controlled evolution by deliberate engineering (teleological intentionality) turns life into a "new ball game." Will the next generation of humans simply want to clean up the genome, making it into a more mathematically-elegant algorithm for the production of conventional human individuals, or will the temptation to tinker with the species become irresistible? This is not just a question of designer babies (created by ambitious parents) or the common science-fiction theme of one malevolent individual gaining some sort of control over our species. One person's eugenic utopia may be another person's genetic dystopia. A world free of T. Rex's or saber-tooth tigers (because they became extinct for whatever natural cataclysmic reasons) may be one thing, but a world populated with intelligent beings that might be thought of as our successors and of our own making (remember HAL in 2001) is quite another.]