 lthough one eats fish, has fins and glides
effortlessly through the water while the other eats hamburgers, wears Reeboks
and drives a car to work every morning, humans and dolphins may have more
in common than people think, especially when it comes to genetics.
 Texas A&M University veterinarians
are comparing human chromosomes to those of dolphins and are finding that
the two share many similarities. The scientists hope to use these similarities
to identify and map the genes of dolphins. Dr. David Busbee and his team
applied human "paints," fluorescently labeled pieces of human
chromosomes, to dolphin chromosomes on microscope slides. When scientists
examined photos taken with a fluorescence microscope, they found dolphin
chromosomes fluorescently tagged with the labeled pieces of human chromosomes
and concluded that dolphins hold many of the same chromosomes as humans.
"We started looking at these
and it became very obvious to us that every human chromosome had a corollary
chromosome in the dolphin," Busbee said. "We've found that the
dolphin genome and the human genome basically are the same. It's just that
there's a few chromosomal rearrangements that have changed the way the genetic
material is put together."
The scientists are trying to determine
if the same similarities are true for individual genes on the chromosomes.
For every dolphin chromosome, they are selecting a gene found on the human
chromosome and seeing if that same gene shows up in the dolphin at the same
place on the chromosome.
"We expect there are a number
of places where the dolphin genome will reflect differences with the human
genome," he said.
These differences will tell scientists
how long ago dolphins and humans embarked down different branches on the
evolutionary tree. According to their genes, Busbee said, dolphins are most
closely related to cows, antelopes and giraffes, and the domestic pig may
be their closest relative.
If scientists can determine the genetic
information shared by humans and dolphins, he said, then they may be able
to save themselves a lot of time and effort in constructing a genetic map
of dolphins. Busbee said they may be able to save as much as 20 years by
tapping into all of the work that has been done mapping human genes and
using this information to identify matching genes in dolphins.
"Nobody has ever done genetics
work on Cetaceans whales, dolphins and porpoises," he said "No
molecular genetics work has been done with this group before."  | 
tamu.edu.