Astrobiology Institute tackles basic questions of life

February 5, 1999 - Scripps Howard News Service

On April 20, 1967, the Surveyor 3 spacecraft landed on the moon, and arriving with it was a creature from Earth - Streptococcus mitis.

When Surveyor 3 was being prepared for launch, somebody apparently coughed on it, and a colony of the common, harmless bacteria was established on a piece of foam insulation that covered one of Surveyor's circuit boards.

The bacteria contamination was discovered in 1969 when Apollo 12 astronauts Pete Conrad and Alan Bean brought back a piece of Surveyor's insulation. The bacteria had been freeze-dried in space, but were quickly revived once back on Earth.

So bacteria, the earliest and most common form of life on Earth, were also the first life form to travel to the moon. The Surveyor contamination accident revealed that bacteria could survive a launch, travel unprotected through the vacuum of space and survive three years on the moon's surface - a place of high radiation, temperatures near absolute zero, and no nutrients. Once dropped into a nutrient-rich petri dish back on Earth, the bacteria came out of "hibernation" and popped back to life. The lesson of the streptococcus space colony wasn't lost on NASA. It showed that life could survive in very harsh environments, even extraterrestrial ones.

Now, more than three decades after the bacteria went to the moon, NASA is establishing the Astrobiology Institute, a joint effort of 11 laboratories - university, private and government - to study life in a unique way. By pulling together researchers from biology, chemistry, genetics, geology, planetary science, astronomy and other scientific fields, the institute plans to apply "hard science" to such philosophical questions as: Where did we come from? Are we alone in the universe? Can we migrate to and transform other planets?

The institute is a scientific response to recent discoveries on the Earth, in the solar system and beyond. Institute scientists, in talks and papers presented at the annual meeting of the American Association for the Advancement of Science, which ended last week, noted several discoveries that, as one said, "have changed our view of the potential for life in the universe":

--The discovery in recent years of more planets outside our solar system than in it. Observations, especially with the Hubble Space Telescope, have shown that planet formation seems to be fairly common around stars. --The realization that life can live under extreme conditions. Biologist Jonathan Trent, in a discussion about a host of terrestrial life forms known as extremophiles, noted that organisms have been found on Earth that can survive in temperatures beyond the boiling point of water, many degrees below freezing, 2.5 miles underground, in extreme acid and base conditions, and even in high radiation inside of a nuclear reactor.

Trent, of NASA's Ames Research Center at Moffett Field, Calif., said that as much as we know about life on Earth, there is an incredible amount we don't know. "We only know about one-tenth of one percent of the microbes that live in the sea," he said. Of the microscopic creatures in freshwater environments and soils, he said, we've identified fewer than 1 percent.

--The discovery that water once flowed on the surface of Mars and may exist below the surface under conditions that would support life as we know it on Earth. A similar discovery raises the possibility of an ocean of liquid water under the ice crust of Europa, one of Jupiter's moons. If Europa's ocean has hot vents or volcanoes on the ocean floor, Trent said, creatures could live there as they do around ocean vents on Earth.

--The realization that life on Earth can be traced back 3.8 billion years, meaning that life began within a billion years of our planet's formation. Because life began quickly on Earth, it also might have begun quickly on Mars, a planet that is believed to have had a dense atmosphere, flowing water and perhaps vast oceans early in its existence.

"Mars had about a 200-million-year period when life could have gotten started," said Jack Farmer, a geologist at Arizona State University and a member of the Astrobiology Institute. Mars became an apparently dead planet as long as 3.5 billion years ago when it lost almost all of its atmosphere. No one is sure what happened to the water, Farmer said, "but maybe it went under the surface. There could be a biosphere - an environment filled with life, probably microbial - on Mars waiting for us to discover it."

Although that might have sounded like wishful thinking only a few years ago, microbes have been found living a couple of miles under the Earth's surface, where conditions might not be much different than they are under the Martian surface.

--The development of bioengineering, which could allow humans to intentionally and quickly develop biological adaptations for themselves, plants, animals and other living things to help with the move into space.

"Humanity may be entering a new evolutionary territory - space - in a manner analogous to the first sea creature crawling out onto the land," said Emily Morey-Holton, a biologist at the Ames Research Center. "This time, however, we are able to document this evolutionary trajectory with modern molecular-biology tools and to engineer the artificial ecologies for evolutionary success."

One of Morey-Holton's particular concerns as life moves off Earth is the role of gravity in everyday life, and in the subtle mechanisms of evolution.

"We live with a one-G environment," she said, referring to the gravitational force that governs us here on Earth. "But as we move out, we have to have a multi-G mentality." Humans living in space, on the moon, on Mars and perhaps other planets will all experience different levels of gravity depending on where they are, she said, and each level of gravity will present unique challenges.

Astronauts working in zero-G already have realized that without gravity, water won't percolate through soil. That makes something as simple as watering a plant a difficult problem. Other processes such as convection and sedimentation, both important climatic and geological phenomena on Earth, don't occur at all in the zero-gravity of space and may not work well in a low-gravity colony on Mars or the moon.

Another interesting question, Morey-Holton said, is what happens to humans who grow up in space, on the moon or Mars? Evolution has given us bodies suited for one G. What happens to bodies developing over generations in lower or higher gravity? Could a person who grows up on Mars find the Earth's stronger gravity overwhelming and be unable to return to the "home planet?"

The questions being addressed by the Astrobiology Institute are seemingly endless, and many are profound. Until now the work that many of these scientists are doing has been the stuff of science fiction. Now, with the establishment of the field of astrobiology, the line between the fiction of the past and the reality of the future seems to be blurring.

The Astrobiology Institute, backed by more than $15 million in federal funding for the next year, is much more than a group of scientists theorizing about what might be out there. In December, two basketball-sized aero-shells will crash onto the Martian surface and release probes that will punch several feet into the soil in search of water. During the next few years more landers will descend on Mars, all looking for signs of life - or past life.

In 2003 a spacecraft will head for Europa in search of the ocean that may be hidden beneath the ice. A life-seeking lander might not be far behind. In 2004 a spacecraft already on its way to Saturn will drop a probe onto Titan, a moon with a dense atmosphere of nitrogen - an ingredient for life as we know it. Another mission, the Titan Biologic Explorer is already on the drawing boards. Sampling missions are also scheduled to land on passing comets to see if they really are the water carriers of the solar system, as some scientists suspect.

Almost all the missions in space for the next decade seem aimed at finding evidence of life out there. While probes look for extraterrestrial life, Earth-bound biologists will push harder to understand what life is and how it comes to be. Finally, there are the scientists such as Morey-Holton who, as she said, will be "looking at how life might be moved beyond our home planet. Humans now have the potential to direct life beyond Earth."

Researchers identify body's fat building enzymes

San Francisco -October 26, 1998

Scientists said Monday they had discovered a major piece in the puzzle of how the human body builds and regulates fat, a finding that may lead to new approaches for treating obesity. A research team led by scientists at the Gladstone Institute of Cardiovascular Disease and the University of California, San Francisco (UCSF), said it was able to isolate a key enzyme that the body uses to produce fat.

The enzyme, called DGAT, joins with other molecules to produce a specific group of fats called triglycerides, which make up more than 95 percent of fatty tissue in humans. Robert Farese, Jr., the principal investigator at Gladstone in San Francisco, said researchers have known about DGAT for several decades but have until now been unable to isolate the elusive enzyme.

Farese said his team's discovery, which was due to be summarized Tuesday in The Proceedings of the National Academy of Sciences, could lead to new drug therapies aimed at treating obesity by blocking DGAT.

"The neat thing about that is that most (obesity) therapies now deal with perturbing brain transmitters that influence a person's appetite, whereas this could work directly at fat tissue to inhibit fat production," Farese said in a telephone interview.

Farese said the finding also could have applications in agriculture because DGAT plays an important role in the synthesis of seed oils, such as canola oil, in plants.

"The DGAT enzyme is the last step in making the triglycerides that become the plant oil, so if you could boost the amount of this enzyme in the plants, you could potentially get more oil per plant," Farese said.

Farese and his fellow researchers were able to isolate the tricky enzyme by using a kind of genetic fingerprinting.

The group had been studying a related enzyme called ACAT, which is involved in cholesterol metabolism. Using the known genetic sequence of ACAT, the researchers were able to then compare it to other unidentified genetic sequences that are available to the public through computer databases.

"Using these databases, we were able to identify a similar gene. We didn't know what it was at first so we tried to see if it was ACAT, and it wasn't. We found that it was this DGAT enzyme," Farese said. Farese said the finding was the "most exciting" he had been involved with but he also warned against overstating the importance of the discovery. Still, he noted that UCSF had filed a for patent on the discovered gene. "We now have the tools to look at this important enzyme and it could lead to important therapies, but it's too early to tell," he said.

Humans Genes Closer To Dolphins' Than Any Land Animals

August 25, 1998 - AP

For years, marine biologists have told us that dolphins share many traits with humans, including intelligence and friendliness. Now, a comparison of dolphin and human chromosomes shows that the genetic make-up of dolphins is amazingly similar to humans. In fact, researchers at Texas A&M University have found that dolphins have more in common with us genetically than cows, horses or pigs.

This information will not only help researchers construct the genetic blueprint of dolphins, but also bolster conservation efforts. Aided by the progress made in mapping the human genome, researchers will continue to identify individual genes on dolphin chromosomes. Busbee estimates it will save them 20 years of work, and the similarities and differences will reveal how long ago humans and dolphins branched off the evolutionary tree.

Researchers at Texas A&M University applied "paints," or fluorescently labeled human chromosomes, to dolphin chromosomes, and found that 13 of 22 dolphin chromosomes were exactly the same as human chromosomes. Of the remaining nine dolphin chromosomes, many were combinations or rearrangements of their human counterparts. Researchers also identified three dolphin genes that were similar to human genes.

Until now, researchers have never been able to do genetic studies of dolphins because they are a protected species, making it difficult to get tissues from them. However, Busbee was able to grow colonies of cells from fetal tissues when a female dolphin miscarried.

"Dolphins are marine mammals that swim in the ocean and it was astonishing to learn that we had more in common with the dolphin than with land mammals," says Horst Hameister, professor of medical genetics at the University of Ulm in Germany.

In the past 15 years, the world's dolphin populations have declined considerably, exacerbated by high levels of PCBs. Researchers speculate that PCBs impair the immune systems of dolphins, leaving them vulnerable to disease.

"If we can show that humans are similar to dolphins, and anything that endangers dolphins is an equal concern for humans, it may be easier to persuade governments to become serious about combating industrial pollution and keeping oceans clean," says Busbee.

By Seema Kumar, Discovery Channel Online News

Scientists Back Inheritance of Jewish Priesthood Designation

July 8, 1998 - AP

Scientists have found fresh genetic evidence that Jews who consider themselves part of the priestly class known as Cohanim really are part of an unbroken line extending back thousands of years.

The Cohanim are said to be descended from Moses' brother, Aaron. Originally they had primary responsibility for offering sacrifices and serving as arbiters and mentors. Today, in Orthodox and some other Jewish congregations, Cohanim are still accorded special duties and privileges.

A Cohan is giventhe honor of reading first from the Torah during a service, and presides over a traditional ceremony for some first-born boys.

Cohanim aren't allowed to marry widows, divorcees or converts. Because of the Jewish belief that the Temple in Jerusalem will be rebuilt and that Cohanim will serve again as priests there, they try to remain spiritually pure. So they stay away from dead bodies, not attending funerals except for those of immediate family, for example.

Many Cohanim have surnames such as Cohen, Kahn, Kane or similar variations. But not all men with such surnames are Cohanim.

Last year, scientists who studied the Y chromosome in modern-day Cohanim reported evidence that the designation truly has been passed from father to son. The Y chromosome is inherited that way, making it useful for such studies.

More evidence appears in a new study, reported by Israeli and British scientists in Thursday's issue of the journal Nature. They looked for variations in the Y chromosome from 306 Jewish men, including 106 self-identified Cohanim, from Israel, Canada and England.

Most Cohanim had the same version of the Y chromosome or close variants that differ because of random mutations. That shows there has been "reasonable adherence to the policy of father-son inheritance," said researcher David B. Goldstein of Oxford University.

By studying how long it would take for the variants to develop, researchers concluded the inheritance of Cohanim status has gone on longer than 700 years and maybe as long as 3,000 years or so, as tradition maintains. The sample also contained 81 self-identified Levites, a designation that began with the Levi tribe after the Exodus and is also supposed to pass from father to son.

The study could not confirm that. The Levites showed too much variety in their Y chromosome variants. That could mean that non-Levite Jews took up the designation in the past, or that the original Levites had a lot of variety in their Y chromosomes.

Rabbi Raphael B. Butler, executive vice president of the Orthodox Union, an umbrella organization of Orthodox congregations, said he doubted the study would affect the designations of Cohan or Levite today. But it's "enlightening" that the results agree with the Jewish tradition, he said.