|
Some of these posts are very old and might contain outdated information. You may wish to search for newer posts instead.
|
callemann
Stranger
Registered: 08/10/05
Posts: 49
Last seen: 4 years, 6 months
|
Evolution of the toxins muscarine and psilocybin in a family of mushroom-forming fung
#18347378 - 05/31/13 01:56 AM (10 years, 11 months ago) |
|
|
Hi! It came a new interesting article today. Thought you might like it if you have access.
Kosentka et al PLOS ONE
http://www.ncbi.nlm.nih.gov/pubmed/23717644
Mushroom-forming fungi produce a wide array of toxic alkaloids. However, evolutionary analyses aimed at exploring the evolution of muscarine, a toxin that stimulates the parasympathetic nervous system, and psilocybin, a hallucinogen, have never been performed. The known taxonomic distribution of muscarine within the Inocybaceae is limited, based only on assays of species from temperate regions of the northern hemisphere. Here, we present a review of muscarine and psilocybin assays performed on species of Inocybaceae during the last fifty years. To supplement these results, we used liquid chromatography-tandem mass spectrometry (LC-MS/MS) to determine whether muscarine was present in 30 new samples of Inocybaceae, the majority of which have not been previously assayed or that originated from either the tropics or temperate regions of the southern hemisphere. Our main objective is to test the hypothesis that the presence of muscarine is a shared ancestral feature of the Inocybaceae. In addition, we also test whether species of Inocyabceae that produce psilocybin are monophyletic. Our findings suggest otherwise. Muscarine has evolved independently on several occasions, together with several losses. We also detect at least two independent transitions of muscarine-free lineages to psilocybin-producing states. Although not ancestral for the family as a whole, muscarine is a shared derived trait for an inclusive clade containing three of the seven major lineages of Inocybaceae (the Inocybe, Nothocybe, and Pseudosperma clades), the common ancestor of which may have evolved ca. 60 million years ago. Thus, muscarine represents a conserved trait followed by several recent losses. Transitions to psilocybin from muscarine-producing ancestors occurred more recently between 10-20 million years ago after muscarine loss in two separate lineages. Statistical analyses firmly reject a single origin of muscarine-producing taxa.
|
thiotimoline
Stranger

Registered: 12/01/12
Posts: 898
Loc: Bay Area
Last seen: 6 years, 3 months
|
Re: Evolution of the toxins muscarine and psilocybin in a family of mushroom-forming fung [Re: callemann]
#18351578 - 06/01/13 12:29 AM (10 years, 11 months ago) |
|
|
Quote:
callemann said: Hi! It came a new interesting article today. Thought you might like it if you have access.
This article is actually open-access! Click on the little blue "PLOS One" icon at the top right.
I hear about the "exclusivity" of producing muscarine versus psilocybin in the Inocybes, but it seems that muscarine loss is not uncommon and psilocybin production evolved only twice in this group. Is there a strong reason to believe in some deeper cause than random (and convenient!) chance? Is it because a similar pattern seems to hold for Conocybes, though the deadly species in that genus produce toxins other than muscarine?
|
PrimalSoup
hyperspatial illuminations



Registered: 11/17/09
Posts: 13,568
Loc: PNW
Last seen: 1 year, 8 months
|
Re: Evolution of the toxins muscarine and psilocybin in a family of mushroom-forming fung [Re: callemann]
#18351997 - 06/01/13 02:50 AM (10 years, 11 months ago) |
|
|
Fascinating - thanks for posting that.
Quote:
Nevertheless, these results reinforce the observation that the loss of muscarine precedes evolutionary gains of psilocybin. Not all muscarine-lacking taxa, however, produce psilocybin. Indeed, psilocybin-containing taxa are quite rare in the family (app. 1% if one accepts a conservative estimate of ca. 500 species).
Lends some credence to the function of psilocybin as a toxic alkaloid expressed for self defense, I suspect. 
PS
--------------------
if you stand too close to the machine it'll start to eat youPrimal's simple tested teks and projects: Wheat Prep 2.0 Acidic Tea Tek Potency Project!
|
fastfred
Old Hand



Registered: 05/17/04
Posts: 6,899
Loc: Dark side of the moon
|
Re: Evolution of the toxins muscarine and psilocybin in a family of mushroom-forming fung [Re: PrimalSoup]
#18356711 - 06/02/13 03:52 AM (10 years, 11 months ago) |
|
|
> Lends some credence to the function of psilocybin as a toxic alkaloid expressed for self defense, I suspect.
I think that involves multiple assumptions there.
Quote:
It is also unclear if muscarine is expressed in mycelia of these fungi; which organisms, if any, are subject to biochemical deterrence; and the extent to which muscarine acts as a biological defense compound.
I'm not sure where they're getting the "muscarine and psilocybin are exclusive" part. The article they provide as a citation for that statement doesn't even contain the word "psilocybin".
Quote:
That is, both toxins have not been found to co-occur in a single species. The biochemical pathways that generate the two toxins are quite different and unrelated. [but...] To resolve any discrepancies in the literature, we used a simple-majority approach or relied on additional reports. For example, Gartz [36] suggests the presence of psilocybin in I. calamistrata. However, both Besl and Mack [3] and Stijve et al. [13] report its absence.
Gartz is one of the authors of this paper!?!
The biggest reveal of this paper is that psilocybin probably evolved about 10 million years ago.
-FF
|
PrimalSoup
hyperspatial illuminations



Registered: 11/17/09
Posts: 13,568
Loc: PNW
Last seen: 1 year, 8 months
|
Re: Evolution of the toxins muscarine and psilocybin in a family of mushroom-forming fung [Re: fastfred]
#18358040 - 06/02/13 11:56 AM (10 years, 11 months ago) |
|
|
"some credence" in the sense that, if muscarine is defensive, and the production of muscarine and psilocybin are exclusive, then it seems plausible that psilocybin may be defensive. 
As to the antiquity - multiple evolutions of psilocybin, but only demonstrated in Inocybaceae.
Interesting, not definitive.
PS
--------------------
if you stand too close to the machine it'll start to eat youPrimal's simple tested teks and projects: Wheat Prep 2.0 Acidic Tea Tek Potency Project!
|
fastfred
Old Hand



Registered: 05/17/04
Posts: 6,899
Loc: Dark side of the moon
|
Re: Evolution of the toxins muscarine and psilocybin in a family of mushroom-forming fung [Re: PrimalSoup]
#18360806 - 06/03/13 12:51 AM (10 years, 11 months ago) |
|
|
I'm just confused what their basis for suggesting they are exclusive. The only evidence I see presented in their article actually contradicted that.
They aren't structurally, metabolically, or otherwise related in any way that I can see. Given that, suggesting they're exclusive would seem to defy reason.
There just seems to be quite a bit of faulty or unsupported reasoning in their article. But the timeline on psilocybin evolution is as good as we'll probably ever get, certainly any time soon.
-FF
|
PrimalSoup
hyperspatial illuminations



Registered: 11/17/09
Posts: 13,568
Loc: PNW
Last seen: 1 year, 8 months
|
Re: Evolution of the toxins muscarine and psilocybin in a family of mushroom-forming fung [Re: fastfred]
#18360866 - 06/03/13 01:13 AM (10 years, 11 months ago) |
|
|
The difference pathways for production confuses me as well, as it doesn't go with the hypothesis that one product replaces the other, and of course there's no explanation of how such a switch occurs. Plus the idea of separate evolution of psilocybin production, that seems a heck of a stretch...
If there is no verifiable exclusive production then the whole idea falls apart, IMHO anyway.
Still found it interesting, however I did have to skim through it as many of the details were indecipherable to me. 
PS
--------------------
if you stand too close to the machine it'll start to eat youPrimal's simple tested teks and projects: Wheat Prep 2.0 Acidic Tea Tek Potency Project!
|
|