Platypus poison!!

Novel venom gene discovery in the platypus. 
Whittington CM, Papenfuss AT, Locke DP, Mardis ER, Wilson RK, Abubucker S, Mitreva M, Wong ES, Hsu AL, Kuchel PW, Belov K, Warren WC.

Abstract

BACKGROUND: To date, few peptides in the complex mixture of platypus venom have been identified and sequenced, in part due to the limited amounts of platypus venom available to study. We have constructed and sequenced a cDNA library from an active platypus venom gland to identify the remaining components.

RESULTS: We identified 83 novel putative platypus venom genes from 13 toxin families, which are homologous to known toxins from a wide range of vertebrates (fish, reptiles, insectivores) and invertebrates (spiders, sea anemones, starfish). A number of these are expressed in tissues other than the venom gland, and at least three of these families (those with homology to toxins from distant invertebrates) may play non-toxin roles. Thus, further functional testing is required to confirm venom activity. However, the presence of similar putative toxins in such widely divergent species provides further evidence for the hypothesis that there are certain protein families that are selected preferentially during evolution to become venom peptides. We have also used homology with known proteins to speculate on the contributions of each venom component to the symptoms of platypus envenomation.

CONCLUSIONS: This study represents a step towards fully characterizing the first mammal venom transcriptome. We have found similarities between putative platypus toxins and those of a number of unrelated species, providing insight into the evolution of mammalian venom.

Genome Biol. 2010;11(9):R95. Epub 2010 Sep 29.

Why is this cool?

 Did you even know that platypi are poisonous? Don't lie. I didn't know and it was interesting to learn that there are poisonous mammals! Here is an interesting question: how does the environment select for poisonous? How does a platypus become poisonous especially since it has no teeth!!?

Platypus mouth that is unable to deliver mind blowing poison.

 Do you see that mouth? No way for poison to be delivered and that is why there is a special structure devoted to terrorizing children who would otherwise love the friendly platypus.

Evil platypus spike for poisoning the trusting.

 Anyway, today's paper goes about attempting to identify the composition of the platypus poison by getting the sequences of genes that are turned on in the poison gland. They found that some of the venom in platypi is similar to venom found in reptiles and fish! Can you imagine that?! Are there genes and peptides in the human body that can be easily converted into poison producing genes? That would depend on if we have the same evolutionary trajectory from reptiles that platypi had.
 Just imagine poison producing humans. Maybe the gland would be under our fingernails and when we scratched one another the poison would be transferred! What would poisonous fingernails be good for?