Not for the duck-billed bottom feeders though. Or for echidnas, also known as spiny anteaters - another iconic Australian species found to carry the unusual hormone. Both produce a long-lasting form of it, offering the tantalising prospect of creating something similar for human diabetes sufferers. Lead researcher Prof Frank Grutzer told the BBC's Greg Dunlop why the researchers had decided to look at the platypus and its insulin mechanisms: "We knew from genome analysis that there was something weird about the platypus's metabolic control system because they basically lack a functional stomach.
They are not the only animals to use insulin against enemies. The gila monster, a venomous lizard native to the US and Mexico, and the geographer cone, a dangerous sea snail which can kill entire schools of fish by releasing insulin into the sea, both also weaponise the chemical. He emphasised that much more research was needed before the discovery could, if ever, lead to a human treatment: "An important experiment is going to be putting this it into mice and see how it affects blood glucose levels.
That's certainly very high on our priority list. We still have to learn a lot more about how this platypus hormone actually works. This platypus, renowned as one of the few mammals that lay eggs, also is one of only a few venomous mammals. The males can deliver a mega-sting that causes immediate, excruciating pain, like hundreds of hornet stings, leaving victims incapacitated for weeks. Now scientists are reporting an advance toward deciphering the chemical composition of the venom, with the first identification of a dozen protein building blocks.
Masaki Kita, Daisuke Uemura, and colleagues note that spurs in the hind limb of the male platypus can deliver the venom, a cocktail of substances that cause excruciating pain. The scientists previously showed that the venom triggers certain chemical changes in cultured human nerve cells that can lead to the sensation of pain. Until now, however, scientists did not know the exact components of the venom responsible for this effect.
To unlock its secrets, the scientists collected samples of platypus venom and used high-tech analytical instruments to separate and characterize its components.
They identified 11 new peptides, or protein subunits, in the venom. Studies using nerve cells suggest that one of these substances, called Heptapeptide 1, is the main agent responsible for triggering pain. Animals end up using the same genes as building blocks for venom because only a subset of the proteins the genes encode have the structural and functional properties to become venoms, he adds. Learning more about how these toxins attack our system and induce inflammation, nerve damage, muscle contraction, and blood coagulation, could teach us how to design drugs with these effects like coagulation for hemopheliacs , or their opposite like new pain relievers.
We first started unraveling the platypus genome in , when it was sequenced and revealed a long list of this marvel of monotreme evolution. The platypus lays eggs, but it also lactates and has hair like mammals, though it has no nipples. It has ten sex chromosomes, which resemble those of birds, but uses genes from mammals and reptiles to fertilize and lay its eggs, which are produced from only one of two ovaries the left one.
It also has fewer smell receptors than other mammals, but this diminished olfaction isn't that big of a deal, because it hunts by detecting its prey's electric current. Not only does the animal itself mystify biologists, but its name has also become a bone of contention among linguists, says Neatorama :.
Pluralizing the creature has proven to be quite a problem not for just laymen, but even to scientists. There is still no universally accepted plural to the word. Register or Log In.
0コメント