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Emperor Reishi
Student of Wisdom



Registered: 09/11/08
Posts: 145
Last seen: 14 years, 6 months
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Sectoring of pure Clone...
#9222772 - 11/11/08 07:29 AM (15 years, 3 months ago) |
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I've read about the sectoring of pure clones, and I've heard discussion of it here on the shroomery before, but have not been able to find any info about the exact cause, and/or the significance... (ie if there are not multiple strains on the given media that sectoring is occuring, what do the sectors represent)
So when we grow out plates and do transfers to isolate a strain after all is said and done I originally though ... "ok, no more sectoring because there aren't multiple strains to compete." So what is this phenomenon.
I have some theories, but i'm not looking to have someone agree with me, I wanna hear what you have to say...
Any input here guys?
-------------------- EmperoR ReishI Looking for: Live Cultures: Maitake[sclerotia forming], Wood Ear[Auricularia Polytricha], Prints: **Psilocybe mexicana, Reishi [other than red], Bioluminessent Cubes & Pan Cyans Available for trade: Live cultures: Reishi[ganoderma lucidum], Shiitake[lentinula edodes], Chicken of the woods[Laetiporus sulphureus], Enoki [Flammulina velutipes], Oyster [Pleurotus ostreatus], Lion's Mane [Hericium erinaceus]
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denger
Mycelium keeper



Registered: 09/19/08
Posts: 1,177
Loc: Unites States of Dreams
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In most cases somatic mutations are responsible for sectoring in a pure strain. There are other processes that might be involved, such as regulatory switching (see http://en.wikipedia.org/wiki/Regulation_of_gene_expression)
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Emperor Reishi
Student of Wisdom



Registered: 09/11/08
Posts: 145
Last seen: 14 years, 6 months
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Re: Sectoring of pure Clone... [Re: denger]
#9222849 - 11/11/08 08:20 AM (15 years, 3 months ago) |
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Well, I read the article you linked to, and it sounds to me like it's not necessarily a degeneration in the culture. It's is straying away from the isolate you wanted which may or may not be beneficial. Would you say that this is just the culture announcing it's need for variation...
Could you result in a quality strain from this sectoring, or is the strain unstable at this point and need to be cross bread to introduce new genetic markers?
-------------------- EmperoR ReishI Looking for: Live Cultures: Maitake[sclerotia forming], Wood Ear[Auricularia Polytricha], Prints: **Psilocybe mexicana, Reishi [other than red], Bioluminessent Cubes & Pan Cyans Available for trade: Live cultures: Reishi[ganoderma lucidum], Shiitake[lentinula edodes], Chicken of the woods[Laetiporus sulphureus], Enoki [Flammulina velutipes], Oyster [Pleurotus ostreatus], Lion's Mane [Hericium erinaceus]
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denger
Mycelium keeper



Registered: 09/19/08
Posts: 1,177
Loc: Unites States of Dreams
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As I said, primary reason is somatic mutations. Same thing is probably responsible for strain senescence to a large degree.
I would not say that it is "announcing" anything, because it cannot. I don't think there is an inherent "need" for variation either. Its just a phenotypical expression of normal biological processes.
Most mutations statistically are the opposite of beneficial, and it frequently takes more then one genetic event to alter the phenotype, so I would not take sectoring of a pure strain as a positive thing. However, whether the strain is "quality" or not depends on your definition of quality. If stability over long time is one parameter of "quality" then no, it is not going to be quality. If, on the other hand you are talking about a psilocybin producing species, and your primary definition of quality is fruiting and activity, then there is no way to tell without trying to fruit it and check the results.
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Emperor Reishi
Student of Wisdom



Registered: 09/11/08
Posts: 145
Last seen: 14 years, 6 months
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Re: Sectoring of pure Clone... [Re: denger]
#9223013 - 11/11/08 09:18 AM (15 years, 3 months ago) |
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By quality I meant stability, over periods of time, of whatever given traits have been observed.
1) So, if a pure strain sector, and you isolate one of these sectors.... those sectors are bound to be unstable as well?
2) And not to sound naive if you have answered this (I just didn't get it) but what do those sectors represent. Is it just random recombinations of DNA, or is it more defined like the isolate is splitting into all possible recombinations of its DNA as if it had sporalated and it's multiple dna possibilities had mated... (or something completely different... or maybe not even scientifically known yet and the reason I can't find the info)
Thanks for your response... It's been insightful...
-------------------- EmperoR ReishI Looking for: Live Cultures: Maitake[sclerotia forming], Wood Ear[Auricularia Polytricha], Prints: **Psilocybe mexicana, Reishi [other than red], Bioluminessent Cubes & Pan Cyans Available for trade: Live cultures: Reishi[ganoderma lucidum], Shiitake[lentinula edodes], Chicken of the woods[Laetiporus sulphureus], Enoki [Flammulina velutipes], Oyster [Pleurotus ostreatus], Lion's Mane [Hericium erinaceus]
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RogerRabbit
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Registered: 03/26/03
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I've never seen sectoring from a clone that was grown from an isolated strain. I have however seen it many times with multispore inoculated fruits. I've also seen it with outdoor cloned fruits from many species. Not all strains that emerge are going to be compatible, and some will remain entwined within the mycelium network, but as separate organisms.
My theory is that more than one of these strains can be present in a single fruit body. The main evidence is that if you grow out each of the sectors from the cloned fruit, they'll in turn produce fruits that are noticeably distinct from each other. RR
-------------------- Download Let's Grow Mushrooms semper in excretia sumus solim profundum variat "I've never had a failed experiment. I've only discovered 10,000 methods which do not work." Thomas Edison
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denger
Mycelium keeper



Registered: 09/19/08
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Re: Sectoring of pure Clone... [Re: RogerRabbit]
#9223842 - 11/11/08 12:09 PM (15 years, 3 months ago) |
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Some strains can be more unstable then others. Sectoring is not unheard of in a pure clone. RR is correct that it is rare.
If you only seen one sector, and you are 100% sure you have a pure clone, then I would recommend subculturing both the sector and the normal grow and seeing what comes out of it. If you see more sectoring, then you probably have an unstable clone. Interesting from scientific point of view, but useless practically.
Another possibility is contamination. Some types of contaminants can co-exist with mycelium, and alter its appearance.
To get back to your questions:
1. Depending on what caused the sectoring, they might result in a more unstable clone, but not necessarily since we dont know what caused it to begin with.
2. Sectors represent different morphology of mycelia. The underlying mechanism is not known for sure. It could be a spontaneous mutant (likely). It could be contaminant. It could be that your strain was not pure to begin with as RR pointed out (this is why i said "pure strain" in bold before).
A picture might be of interest here. Also, what species are we talking about?
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Emperor Reishi
Student of Wisdom



Registered: 09/11/08
Posts: 145
Last seen: 14 years, 6 months
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Re: Sectoring of pure Clone... [Re: denger]
#9229085 - 11/12/08 08:41 AM (15 years, 3 months ago) |
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SO, I was re-reading through a few sections of
Mushroom Cultivator: A Practical Guide to Growing Mushrooms at Home
and I found another answer to back up what you were saying already:
p338 sectoring of old cultures
As pure cultures grow old and becomesenescent, they produce ever greater quantities of sectors due to the accumulation of random mutations. Repeated subculturing of the culture gives accumulated mutations a chance to express themselves. A strain which has reached this condition is no longer pure, and should not be used for cultivation.
-------------------- EmperoR ReishI Looking for: Live Cultures: Maitake[sclerotia forming], Wood Ear[Auricularia Polytricha], Prints: **Psilocybe mexicana, Reishi [other than red], Bioluminessent Cubes & Pan Cyans Available for trade: Live cultures: Reishi[ganoderma lucidum], Shiitake[lentinula edodes], Chicken of the woods[Laetiporus sulphureus], Enoki [Flammulina velutipes], Oyster [Pleurotus ostreatus], Lion's Mane [Hericium erinaceus]
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fastfred
Old Hand



Registered: 05/17/04
Posts: 6,899
Loc: Dark side of the moon
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To hazard my opinion... I think most of this sectoring from clones is simply due to the fact that you are using already differentiated cells to start your culture. These cells are bound to exhibit different morphology due to methylation patterns, chromatin differences, DNA binding proteins, etc., etc..
It is like taking random cells from your body and culturing them. Some will produce liver tissue, some heart tissue, etc.. Plants and fungal cells can often be induced to revert back to a stem-cell like state, but they are never going to be exactly the same as an undifferentiated cell.
-FF
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Emperor Reishi
Student of Wisdom



Registered: 09/11/08
Posts: 145
Last seen: 14 years, 6 months
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Re: Sectoring of pure Clone... [Re: fastfred]
#9272104 - 11/19/08 12:48 PM (15 years, 2 months ago) |
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Quote:
fastfred said: To hazard my opinion... I think most of this sectoring from clones is simply due to the fact that you are using already differentiated cells to start your culture. These cells are bound to exhibit different morphology due to methylation patterns, chromatin differences, DNA binding proteins, etc., etc..
It is like taking random cells from your body and culturing them. Some will produce liver tissue, some heart tissue, etc.. Plants and fungal cells can often be induced to revert back to a stem-cell like state, but they are never going to be exactly the same as an undifferentiated cell.
-FF
Im not sure if i understand you completely to be quite honest, but from my understanding of differentiated cells, they are cells that do not have a specialized purpose and then change, due to need, into a cell that performs a specific function, such as turning into liver tissue as you mentioned....
So are you saying that using tissue sample from the mycellium would be beneficial over cloning a fruit )because the fruit cells have become differentiated...
interesting... i dunn oif thats what you are asying or not, but either way do you have a reference where maybe i could read a little more about this
thanks
-------------------- EmperoR ReishI Looking for: Live Cultures: Maitake[sclerotia forming], Wood Ear[Auricularia Polytricha], Prints: **Psilocybe mexicana, Reishi [other than red], Bioluminessent Cubes & Pan Cyans Available for trade: Live cultures: Reishi[ganoderma lucidum], Shiitake[lentinula edodes], Chicken of the woods[Laetiporus sulphureus], Enoki [Flammulina velutipes], Oyster [Pleurotus ostreatus], Lion's Mane [Hericium erinaceus]
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fastfred
Old Hand



Registered: 05/17/04
Posts: 6,899
Loc: Dark side of the moon
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You might look at: http://en.wikipedia.org/wiki/Cellular_differentiation
It's kind of a complex and poorly understood topic. Some organisms have little problem reverting to a stem-cell like state, but there will always be some effect from having already differentiated.
That's my guess as to why seemingly identical cells can perform differently under the same conditions. I don't really buy into the idea that multiple individuals get incorporated into the same fruit body, but I suppose it's possible. It would not be terribly hard to test that theory. All you'd have to do is grow strains with distinct markers (phenotypes) and see if you could recover both strains from a fruit body clone.
Another possibility could be di-mon mating, which could be tested for with a few mating experiments.
It would be nice to figure this out, but I doubt anyone really cares enough to do the experiments. It's usually just a lot of talk with little action here.
-FF
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LightShedder
Trading currencies



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Re: Sectoring of pure Clone... [Re: fastfred]
#9274785 - 11/19/08 08:31 PM (15 years, 2 months ago) |
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I probably look at it too simply but the way I see it...
If you throw spores onto agar there will be hundreds of different substrains. If you don't isolate any of these down to single sector monocultures and just grow out the multiple spore substrains, then take a piece of flesh from a fruit that grew out from the MS, if you drop the tissue onto agar you will see approximately 5 substrains sector out (possible a little more or less). I don't know the scientific reason for this. If you isolate out those sectors and test them out you will see differences in all of those substrains that came from one piece of flesh. I have never taken flesh from a clone because I kinda like to keep it a generation or 2 away from spores so I don't know what happens when cloning pure clones.
As for senescence, If you always grow out spores every 6 months or so and take spore prints from that MS grow and do your production clone work from that MS grow then you should be able to avoid any noticeable degradation for 10 years IMO.
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kindly-garden
Stranger

Registered: 02/02/20
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..interesting to come across this thread.
I also have been surprised to observe sectoring on a clone.
Here is a photo of some sectoring action on some clones I took from two supermarket 'cup' mushrooms.
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