St.
Paul, MN (11/24/98)- Echoing the fictional science seen in Jurassic Park,
scientists have revived bacteria from the guts of bees preserved in 20 million
year old amber.
Researchers at California Polytechnic State University extracted bacteria
from the abdomens of bees that had been encased in amber for at least 20 million
years. The amber came from the Dominican Republic. The amber is dated at 25
and 40 million years based on the microscopic fossils found in the geographic
strata in which the amber was found. The researchers instituted rigorous decontamination
procedures to assure that the material being extracted was truly ancient,
rather than a modern bacterial contaminant.
Researchers placed the extracted material in Petri dishes containing a nutrient
solution. Within two weeks, bacteria subsequently identified as Bacillus sphericus
grew in the culture. A comparison of the DNA of ancient and modern bacteria
appeared to confirm that the bacteria had indeed grown from the ancient spores.
Morphological, enzymatic and biochemical identification methods were used
to make a specific identification.
"The genetic makeup of these bacterial strains holds many possibilities.
"We have discovered a brand new source of organisms that could produce life-saving
pharmaceuticals or be used in valuable industrial processes," said Dr. Raul
Cano, California Polytechnic State University.
The apparent isolation of living bacteria from a 20 million year old specimen
calls into question the consensus view that DNA is not stable enough to survive
for such long periods. More studies will be required before skeptics in the
biology research community are convinced.
Biologists have been attempting to isolate ancient DNA since the 1930's.
The field gained momentum in the 1980's following the development of the polymerase
chain reaction (PCR). PCR screening methods allowed researchers to isolate
and amplify fragments of DNA from ancient sources. However this research involved
cloning DNA from much more recent specimens, including the zebra-like quagga
(100 year old specimen) and human mummies (several thousand years old). Dr.
Cano is the first to extract living bacteria from such an ancient source.
Other researchers are attempting to extract DNA from preserved plant specimens,
some centuries old. Dr Craig Liddell and colleagues at New Mexico State University
sifted through a collection of specimens collected since 1891 to identify
those with a specific rust disease, caused by the fungus Puccinia grindeliae.
They expect that comparing new and old specimens of the fungus could help
identify potential biocontrol uses for eradicating certain weeds.
Dr. Jean Beagle Ristaino of the North Carolina State University, Raleigh
is taking a similar approach to the study of Phytophthora infestans, the fungus
that destroyed the Irish potato crop in the last century, bringing on the
Great Famine. The fungus still poses a threat, so it is more important than
ever to understand the biology of this organism. Dr. Ristaino is analyzing
specimens that were collected before the mass movement of plant materials
common in the practice of modern agriculture.
"We are primarily concerned with genetic changes that have occurred in populations
of organisms during the past tens or hundreds of years up to the present,"
says Dr. Kevin McCluskey, University of Kansas Medical Center. "Fortunately,
these studies are not as difficult as looking at ancient bacteria in amber."
The research was presented at a symposium titled, "Beyond Jurassic Park:
Accessing Genetic Information Hidden in Herbaria and Archival Plant, Microbe
and Insect Specimens," held during a joint meeting of the American Phytopathological
Society and the Entomological Society of America, November 8-12.
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