Reptile & Amphibian Forums

This is the paper where we describe the first cobra-style neurotoxin to be isolated from a ratsnake. Cool

Cheers
Bryan
alpha-colubritoxin paper

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Dr. Bryan Grieg Fry
Deputy Director
Australian Venom Research Unit
University of Melbourne

www.venomdoc.com

That was one of the most difficult reads I have ever done. I i was an English major in college. Neat stuff, if I understand ti correctly.

S~

>>That was one of the most difficult reads I have ever done. I i was an English major in college. Neat stuff, if I understand ti correctly.
>>
>>S~

Hi mate

Yep, you probably understood it correct, we isolated the classic cobra style neurotoxin from ratsnakes. Not quite what we expected when we set out to examine the venom evolution in snakes but it makes perfect evolutionary sense never-the-less. Go to the venomous forum if you want a bit more info as there is a thread there discussing it.

Cheers
Bryan
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Dr. Bryan Grieg Fry
Deputy Director
Australian Venom Research Unit
University of Melbourne

www.venomdoc.com

Thanks, Bryan. Very interesting stuff.

Hope it gives us some leads in the study of ratsnake taxonomy or the origins of the ratsnake/racer clade.

Regards,

Terry

Hi mate

This goes a bit beyond that and looks at venom evolving at snake family level relationships rather than individual genera. There has already been a very good paper by Utiger et al on the ratsnake taxonomy. Elaphe has of course been a taxonomical dumping ground for a large, disparate group of snakes that only superficially resemble each other but it turns out that there are several full genera lurking within there. This is the same situation that happened with the 'colubrids', with anything that wasn't obviously and elapid or viper being thrown in there, however it turns out that there are a half dozen families in there, some of which are much much closer to cobras than to cornsnakes.

Cheers
Bryan
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Dr. Bryan Grieg Fry
Deputy Director
Australian Venom Research Unit
University of Melbourne

www.venomdoc.com

Greetings Mr. Frye,

What I was wondering was if isolating the venom would enable us to be more accurate comparing genera or species in genera with large numbers of species. I'm especially interested in the Elaphe, including the species that have been removed from the original Elaphe genus and put in new or resurrected genera. What you said was, however, that it could be used to look at family level of snakes which were dumped in the Colubridae, like genera were dumped in the Elaphe.

I have a question as a result. Do you think that Coelognathus, which contains 'radiatus', the species you got the venom from, represents an independent family?

Also, I have some comments. The genera Coelognathus and Gonyosoma had already been separated from Elaphe before Utiger et al. made their proposal in 2002. Utiger et al. proposes to split about half dozen new or resurrected genera from the remaining Elaphe. Some problems with the proposal include not having enough outlying genera to compare their results to and the fact that many of the proposed new genera seem very close on their family tree.

A couple more questions. Do you think any of the species that remained in the Elaphe before Utiger et al. possess the venom that radiatus does? Do you think any of the other species in Coelognathus possess this venom? How about Gonyosoma?

I think more work needs to be done on the Elaphe to resolve problems with that genus and also would suggest that the genus should still be in the same family and subfamily with Coelognathus and Gonyosoma even if they don't have any venom and the others do. I believe Utiger et al. did a good job with their research. Good to be moving forward with ratsnake taxonomy. I'm also happy to see the work you're doing with the venom research. I'll be looking forward to future articles. Thanks,

TC

>>What I was wondering was if isolating the venom would enable us to be more accurate comparing genera or species in genera with large numbers of species.

It is certainly a character worth comparing. However, we have looked at venom as a taxonomical tool and found that it evolves at such a sizzling rate that the taxonomical signal quickly becomes blurred, even between closely related species.

>>
>>I have a question as a result. Do you think that Coelognathus, which contains 'radiatus', the species you got the venom from, represents an independent family?

Not a chance. It is a typical member of the Colubrinae snake family and is nothing special by being venomous since this is the basal condition.

>>

>>
>>A couple more questions. Do you think any of the species that remained in the Elaphe before Utiger et al. possess the venom that radiatus does? Do you think any of the other species in Coelognathus possess this venom? How about Gonyosoma?

Yep. Have a look at the publications section of my webpage. In the LC/MS study we showed the widespread presense of venom (including in other such typical 'non-venomous' snakes such as Gonyosoma).

>>
>>I think more work needs to be done on the Elaphe to resolve problems with that genus and also would suggest that the genus should still be in the same family and subfamily with Coelognathus and Gonyosoma even if they don't have any venom and the others do.

They all do. The only exception may be the narrow American clade containing such genera as Lampropeltis/Pantherophis/Pituophis. It 'appears' that the common ancestor had undergone a secondary loss of the venom and reverted back to the more primative constricting condition. We are working on that right now to sort it out one way or the other. Loss of venom is not without precedent, it has occured even within the highly advanced venomous snakes sucha as the elapids. Two lineages of sea snakes for example have independently gone well down the road towards losing their venom entirely since they are specialising in eating fish eggs, their fangs are stubs and the venom glands greatly atrophied. Similarly, the Australian coral snakes (Simoselaps) eat termite eggs and are also evolving towards a non-venomous state.

> I believe Utiger et al. did a good job with their research. Good to be moving forward with ratsnake taxonomy. I'm also happy to see the work you're doing with the venom research. I'll be looking forward to future articles. Thanks,
>

Fangs for that mate.

Cheers
Bryan
-----
Dr. Bryan Grieg Fry
Deputy Director
Australian Venom Research Unit
University of Melbourne

www.venomdoc.com

Greetings again:

[[>>>>What I was wondering was if isolating the venom would enable us to be more accurate comparing genera or species in genera with large numbers of species.
>>
>>It is certainly a character worth comparing. However, we have looked at venom as a taxonomical tool and found that it evolves at such a sizzling rate that the taxonomical signal quickly becomes blurred, even between closely related species.
>>
>>>>
>>>>I have a question as a result. Do you think that Coelognathus, which contains 'radiatus', the species you got the venom from, represents an independent family?
>>
>>Not a chance. It is a typical member of the Colubrinae snake family and is nothing special by being venomous since this is the basal condition.
>>
>>>>
>>
>>>>
>>>>A couple more questions. Do you think any of the species that remained in the Elaphe before Utiger et al. possess the venom that radiatus does? Do you think any of the other species in Coelognathus possess this venom? How about Gonyosoma?
>>
>>Yep. Have a look at the publications section of my webpage. In the LC/MS study we showed the widespread presense of venom (including in other such typical 'non-venomous' snakes such as Gonyosoma).]]

Thanks for the great response and info.

[[>>>>I think more work needs to be done on the Elaphe to resolve problems with that genus and also would suggest that the genus should still be in the same family and subfamily with Coelognathus and Gonyosoma even if they don't have any venom and the others do.
>>
>>They all do. The only exception may be the narrow American clade containing such genera as Lampropeltis/Pantherophis/Pituophis. It 'appears' that the common ancestor had undergone a secondary loss of the venom and reverted back to the more primative constricting condition. We are working on that right now to sort it out one way or the other. Loss of venom is not without precedent, it has occured even within the highly advanced venomous snakes sucha as the elapids. Two lineages of sea snakes for example have independently gone well down the road towards losing their venom entirely since they are specialising in eating fish eggs, their fangs are stubs and the venom glands greatly atrophied. Similarly, the Australian coral snakes (Simoselaps) eat termite eggs and are also evolving towards a non-venomous state.
>>
>>> I believe Utiger et al. did a good job with their research. Good to be moving forward with ratsnake taxonomy. I'm also happy to see the work you're doing with the venom research. I'll be looking forward to future articles. Thanks,
>>>
>>
>>Fangs for that mate. ]]

Excellent. I can readily see the loss of an adaptation like venom. Modern Elaphe are quite advanced/evolved. My ideas concerning the taxonomy and evolution of the group from Old World to New are along the same lines of "evolving" constriction. Maybe it all fits together

Terry Cox/Ratsnake Haven
(Ratsnake Haven's Gallery at Kingsnake.com's Photo Gallery)

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Ratsnake Haven: Elaphe schrencki, dione, bimaculata, mandarina, conspicillata, porphyracea, taeniura, situla, and emoryi.

No worries mate. Glad to help.

Cheers
Bryan
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Dr. Bryan Grieg Fry
Deputy Director
Australian Venom Research Unit
University of Melbourne

www.venomdoc.com