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Now that we have a map of
the human genome, we have to
learn how to read it and
figure out which gene does
what.
Of the estimated 30,000
genes in the human genome,
we have very little idea
about what each one does.
One way of studying genes is
to directly compare the
entire genome with other
organisms. This is called
comparative genomics.
The human genome is
extremely complicated. By
comparing it with the
genomes of other species,
such as mice or fruit flies,
we gain insights into the
similarities and differences
and can learn more about the
function of human genes.
The organisms scientists
are using in comparative
genomics are known as model
organisms. That is, they
provide a model against
which the human genome can
be studied. It doesn't
matter that we have two legs
and mice have four, or that
we have opposable thumbs and
mice have claws. On a DNA
level, humans and other
organisms aren't that
different. On average, the
DNA sequence of mouse and
human genes is 85% similar.
Since 1995, the genomes
of more than 180 organisms
have been sequenced. These
include chimpanzee, mouse,
rat, pufferfish, fruit fly,
sea squirt, roundworm,
baker's yeast, the bacterium
Escherichia coli,
kangaroo, honey bee, dog and
chicken.
In 2008, the platypus
genome was sequenced by
Australian and American
researchers. Analysis of the
genome showed genetic
similar ities to reptiles,
fish and birds, giving clues
to the evolutionary origins
of this egg-laying mammal.
For updated information
on completed genomes:
http://www.genomenewsnetwork.org |
