Advancements In Genomics Foster
Deep Sea Discoveries Led By Scripps
how creatures survive in harsh environment
may lead to clues for healthier food, searching for life on
other planets, and advances in biotechnology
By Mario Aguilera
At one time,
scientists wondered whether life existed in the deep recesses
of the world’s oceans. What kinds of creatures, they wondered,
could withstand the dark, cold and extreme pressure of such
Researchers at Scripps
Institution of Oceanography at the University of California,
San Diego, and their colleagues have used innovations in genomics
research to begin to develop an accurate portrayal of deep sea
life forms and how they survive in the harsh conditions of the
Institution Professor Douglas Bartlett discussed the new findings
at the American Chemical Society’s (ACS) national meeting
in San Diego on Monday, March 14, 2005. Related research was
published in a scientific paper in the March 4 issue of the
In the paper and ACS
presentation, Bartlett and colleagues at the University of Padova
(Italy), presented the first genetic blueprint for bacterial
life in a cold deep-sea environment.
They also presented
a detailed analysis of how the bacteria’s genetic makeup
allows it to function in high-pressure environments. These findings
may help lay the groundwork for a variety of research outside
of the deep ocean, including the application of deep sea bacterial
genes for improving human nutrition and degrading pollutants,
and calculating possibilities for life in pressurized environments
elsewhere in the solar system.
live in a world that is physically very different from the skin
of the planet in which we humans reside,” said Bartlett,
who is part of the Scripps Marine Biology Research Division.
“They live in a world where temperature, for the most
part, doesn’t vary very much, but pressure as they move
up and down the water column can. They sense that pressure.”
The overwhelming majority
of the volume of the planet where life exists, more than 75
percent, exists in the deep sea, while some 20 percent exists
in the shallow water environment and a mere half of a percent
is on land.
Extreme deep ocean
conditions include near freezing temperatures and up to 15,000
pounds per square inch of “skull-crushing” pressure.
Scientists say precious information lies in discovering how
organisms have adapted and evolved to such conditions.
Bartlett and his colleagues
probed the genetic makeup of Photobacterium profundum,
a bacterium that copes with pressures of 4,000 pounds per square
inch. The researchers grow the microbes in high-pressure cylinders
kept cold and dark in Bartlett’s laboratory at Scripps.
genetic analyses revealed a creature that can sense changes
in pressure using a natural barometer-like mechanism, which
adjusts the flexibility of its membranes to cope with different
levels of pressure.
a protein within the membrane that gets squeezed when the cells
experience higher pressure, and that triggers a signal transduction
event that activates the expression of genes that help the cells
to adapt to the increased pressure,” said Bartlett. The
scientists found other tantalizing discoveries in Photobacterium
profundum, including a novel fermentative process, adaptations
to electron, proton and nutrient transport across membranes
and a large number of previously unknown genes.
Scripps has been a
pioneer in researching life in the deep ocean abyss for more
than 50 years. Bartlett’s studies follow the pioneering
work in the 1950s of Claude ZoBell, who provided the first evidence
of deep sea high-pressure microbes, and research begun in the
1960s by Art Yayanos, who was the first to isolate pure cultures
of high-pressure-adapted microbes from their native environments.
This work was funded
at Scripps Institution by the National Science Foundation.
Media Contacts: Mario Aguilera or Cindy Clark