CSHL scientists are part of consortium that sequences platy...( By any account the platypus is an od...),Health

By any account, the platypus is an odd creature. Its got a broad, rubbery bill that brings to mind a duck.but it swims more like a beaver.yet it lays eggs and can inject poisonous venom, like a reptile. No wonder it was considered an elaborate hoax by scientists who examined the first specimen pelt shipped to England from the colony of New South Wales in 1799.

In the May 9 issue of Nature, a consortium of scientists including Cold Spring Harbor Laboratorys (CSHL) Gregory J. Hannon, Ph.D., published results of an international effort to sequence the platypus genome. It reveals evolutionary secrets that go far beyond the obvious fact that the creature, found exclusively in eastern and southern Australia, including the island-state of Tasmania, is neither a typical mammal nor typical reptile.

In fact, the platypus is a member of a mammalian species called the monotremes, which includes only four other subspecies (the other four being echidnas, varieties of spiny anteaters). The monotremes diverged from other primitive mammals about 166 million years ago, in the late Jurassic period -- a fact corroborated indirectly in the newly sequenced genome.

The broad purpose of our consortium was to understand features unique to the platypus and other monotremes, by identifying in its genome various innovations performed by evolution over eons of time, said Dr. Hannon, a CSHL professor. The evidence of how these innovations occurred, quite literally, is written in the sequence of the nucleotides in the platypus genome.

Take the platypuss distinct mode of rearing its offspring. All of the mammals, in addition to being warm-blooded, can be grouped according to their modes of gestation. Marsupials like the kangaroo rear profoundly immature young in external pouches for extended periods of time. Eutherian mammals like mice and humans protect their progeny for lengthy perio
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