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Slime Mould / Slime Mold

FuzzyLord

FuzzyLord

Junior Acolyte
Joined
Nov 6, 2004
Messages
69
(Excerpted from a thread in IHTM.)
RE: A slime mold aggregation called a "grex."

Slime Mold ?

... This is the motile phase of the life cycle of slime molds. Slime molds are amoeboid. To reproduce, the amoebas flow together and form a slug-like body called a grex. One celled animals come together to form something resembling a single macroscoping organism. The grex scoots about looking for a spot to rest. WHen it finds what it likes (good schools?), it becomes a "fruiting body", a bulb on a stalk. The seeming macroscopic animal becomes like a tiny plant. The fruiting body matures, bursts, and sends out spores which settle to the ground. In a moist environment, each spore becomes a new amoeba.

Why such a life cycle? Don't ask me; I just live here.

Anyway, if you poke a grex with a stick, it might lose its cohesion. This is also consistent with the observation that it fell apart into many smaller black worms as opposed to a pile of distinguishable mollusc innards.

Here is a web page on slime molds:

http://www.discoverlife.org/nh/tx/Slime_Molds/

They have a lot of photographs, but I found none that seem to bear out my hypothesis. ...
 
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I warned you about the Slime Moulds...

http://www.newscientist.com/blogs/short ... compl.html

Simple slime mould forms complex tissue
20:15 11 March 2011

Picture of the day

Caitlin Stier, contributor

dickinson1HR.jpg
(Image: Daniel Dickinson)

Single-celled slime moulds work together to improve their chances for survival. Now Daniel Dickinson and his colleagues at Stanford University in Palo Alto, California, have discovered that the humble slime Dictyostelium discoideum forms a specialised tissue known as a polarised epithelium that rivals forms found in multicellular animals. The findings suggest the building blocks for multicellularity existed long before the first animals evolved.

When food is scarce for the slime mould, a fungus-like creature that lurks in damp soils, they join up to create a stalk and cap structure that spreads their spores to a new home. The tip of this fruiting body is made up of the polarised epithelium (pictured above). Proteins similar to the animal equivalents of alpha- and beta-catenins (in orange) help the slime mould organise components within each cell to specialise the function of the overall tissue.

Journal reference: Science, DOI: 10.1126/science.1199633
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ramonmercado said:
I warned you about the Slime Moulds...
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My shower is a 'glass' cabinet type you enter through a door. In recent months, I have taken to leaving it open after use.

The other day I visited the bathroom, and noticed I'd left the door closed, so I opened it. But suddenly this puzzled me - why did I leave it open?

It took me a while to remember that if the door was left closed, there was a narrow gap at the bottom which remained damp, and encouraged the growth of a nasty black mould there. With the door open the area soon dried out, so no mould!

(I've only had this shower unit a few months - the previous one, a curtained variety, used to suffer from mould all over the place. So far the new one has been mould-free, apart from the problem mentioned above.)
 
More Dickian Slime Moulds.

Slime mould spreads through world's motorways
http://www.newscientist.com/blogs/onepe ... gh-wo.html
14:23 14 March 2012
Maps
Jacob Aron, technology reporter


(Image: Andrew Adamatzky, University of the West of England)

A yellow goo has invaded the world's motorways, spreading from capital cities to the furthest reaches of the transport network and devouring everything in its path. The infestation was unleashed by Andrew Adamatzky, a researcher of unconventional computing at the University of the West of England in Bristol, along with colleagues from universities around the globe.

Thankfully, Adamatzky's experiments actually took place on agar plates overlaid on maps. He has previously used Physarum polycephalum, a yellow slime mould, to map the motorways of the UK and Mexico and has now extended the work to cover 12 other regions.

The slime mould is surprisingly good at finding the most efficient route to food, despite being a single-celled organism with no brain or central nervous system. Adamatzky and colleagues used oat flakes to map out the major cities of Africa, Australia, Belgium, Brazil, Canada, China, Germany, Iberia, Italy, Malaysia, Mexico, the Netherlands, the UK and the US, then placed the slime mould at the capital city of each and allowed it to grow.

Each of the resulting slime-mould networks at least partly matched the real motorway network, though some were closer than others, with Belgium, Canada and China being particularly accurate. The team speculate that the resemblance is due to the fact that road networks are based on unplanned paths that were also originally chosen by living creatures, whether they were early humans or roaming cattle.
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Truly PKD territory.

Brainless slime mould has an external memory
http://www.bbc.co.uk/nature/19846365
By Ella Davies
Reporter, BBC Nature

The "remarkably intelligent" slime mould

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Slime moulds use a form of spatial "memory" to navigate, despite not having a brain, a study has found.

Scientists in Australia studied the organisms in an experiment normally used to test robots.

They found that the slime mould could navigate around a U-shaped maze to a food source, using their slimy deposits.

Researchers compare its path-finding method to Hansel and Gretel's breadcrumb trail.

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Their full findings are published in the journal Proceedings of the National Academy of Sciences.

"A slime mould is not a fungus or mould, but is in fact a protist, which is really the odds and ends of the natural world that don't fit in with the rest of our taxonomic grouping system," said PhD student Christopher Reid who led the study.

"They are truly alien creatures and yet they are all around us: all over the world, preying on yeast, bacteria and fungi, out of sight in the undergrowth."

Following on from earlier research into the behaviour of the bright yellow slime mould, Physarum polycephalum, Mr Reid and colleagues form the University of Sydney, Australia, set out to test its navigational abilities.

They placed the organism, which Mr Reid described as a "large, blob-like cell", on one side of a dish of agar gel.

On the other side, researchers placed a sugary food source that they knew the slime mould would be attracted to.

In a test more commonly used to analyse the artificial intelligence of robots, they placed a U-shaped trap between the slime mould and its food source to understand how the organism moved around its environment.

"The whole organism is made up of bits of pulsating tissue, which are constantly expanding and contracting, using a similar mechanism to our own muscle cells," explained Mr Reid.


The mould at the top was attracted to the sugar solution below the maze
"Each part changes the speed at which it pulsates according to what it can sense in the environment around it - for example food, light or heat - which are detected by chemical receptors on the cell's surface."

"The pulsating parts are also influenced by the throbbing of their neighbours within the cell, which means that they can communicate with each other, to pass information through the organism about what is happening in the environment outside. The different speeds of contraction directly influence which direction the cell will then move in."

In their experiment, Mr Reid and colleagues observed the slime mould exploring the dish, leaving a trail of slime behind wherever it went.

According to the scientists, this slime trail was key to the organism's path-finding because it acted like a trail-marker, comparable to Hansel and Gretel's trail of breadcrumbs.

They found that the slime mould did not revisit areas it had already investigated.

"In essence, the slime mould is memorising where it has been - storing this memory in the external environment and recalling the information when it later touches the slime-coated area," said Mr Reid.

Of the moulds tested, 96% successfully found their way to the sugary substance, taking on average 57 hours to do so.

But when researchers covered the whole dish in slime only 33% were able to reach their goal within the 120-hour time limit.


The cell moves by expanding a network of pulsating tissues
"Without the benefit of memory, the slime moulds spent almost 10 times longer pointlessly re-exploring areas they had been before," said Mr Reid.

The findings are the first to identify 'memory' in an organism without a brain or central nervous system.

Although, according to the scientists, the internal memory of higher, multi-cellular organisms probably did not directly evolve from this externalised system, the findings offer insight into how ancient organisms behaved.

Mr Reid said that further research will now focus on what other information the slime trail may hold.

"For a single-celled organism, it has continually surprised researchers with its abilities, such as solving mazes, anticipating periodic events, and even making irrational decisions like we do," he told BBC Nature.

"It is truly a remarkable creature that is redefining our notions of 'intelligence'."

Join BBC Nature on Facebook and Twitter: @BBCNature.
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ramonmercado said:
I warned you about the Slime Moulds...
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And more on slime moulds. PKD would have loved this.

It is perhaps the unlikeliest duet in musical history. And for one half of the pair – a single-celled organism that was among the first lifeforms to appear on Earth – it has been a long time coming.

A slime mould attached to a ground-breaking “biocomputer” will take centre stage at a music festival in Plymouth next month, where it will play the piano alongside the computer’s human creator.

In a pioneering technique, the mould has been hooked up to a series of electrodes by researchers at Plymouth University and is capable of creating a musical response to the sound of piano keys. ...

http://www.independent.co.uk/news/s...ing-of-plasmodium-piano-sonatas-10032706.html
 
Yes - "Le Blob" is a type of "slime mold."

This particular category of organism(s) has always been a headache for taxonomists. The most obvious reason is because these critters sometimes operate as independent microorganisms, but also sometimes operate as participating "cells" within an encompassing macroorganism.
 
I thought Le Blob was what the French called Boris Johnson and Donald Trump!:mcoat:
 
Multiple sexes ?

How many are they ?
 
feinman said:
Sounds like pronoun hell...
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And just think of all those dating apps...

Seriously, this is an astonishing organism, which demonstrates some rudimentary intelligence and memory. The French scientists have been conducting experiments showing blobs navigating through mazes to locate a food source. If one blob that "knows" the route through a maze is introduced to another blob, it somehow imparts the knowledge of the route to the food. Slime moulds can vary from microscopic single cells to macro-organisms several square metres in size (that old sci-fi movie referenced above wasn't that far from the mark!).
These are surely up there with tardigrades and the Boquila trifoliata "chameleon vine" as the world's most alien like organisms.
 
James_H said:
That would be 'les blobs' but anyway, keep the politics out of it.
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Of course, I was referring to them in the singular sense, not when they're together...:axem:
 
A bit off-topic, I had a friend growing-up in Jersey who's parents were French. His dad used to buy Ouest France, basically translating as West France.
I saw it more as 'Where Is France?'
 
I thought that the media coverage was poor as it didn't clarify where and how it was discovered.
 
AlchoPwn said:
You better believe it, after all, I am made of rats and snails and puppydog tails. Damn that rhyme is sexist.
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I'm sure I saw that once on the ingredients list of a keema curry.
 
blessmycottonsocks said:
Ouest France reporting a mysterious growth at the Paris Zoological Park. ...
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JamesWhitehead said:
It resembles a slime-mould to me but I'm assuming that has been eliminated.
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It appears there may be some confusion about this story and the exhibit. "Le Blob" does not represent an anomalous newly-discovered organism. It is a common slime mold found all around the world, and the Paris Zoological Park simply gave it a dedicated exhibit to highlight its unique features.
 
In addition to an ability to "learn" from experience, slime molds of Le Blob's species have been demonstrated to impart learned behavior to another, untrained, member of the species.
Giant cell blob can learn and teach, study shows

Summary:
It isn't an animal, a plant, or a fungus. The slime mold (Physarum polycephalum) is a strange, creeping, bloblike organism made up of one giant cell. Though it has no brain, it can learn from experience, as biologists have demonstrated. Now the same team of scientists has gone a step further, proving that a slime mold can transmit what it has learned to a fellow slime mold when the two combine.
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It isn't an animal, a plant, or a fungus. The slime mold (Physarum polycephalum) is a strange, creeping, bloblike organism made up of one giant cell. Though it has no brain, it can learn from experience, as biologists at the Research Centre on Animal Cognition (CNRS, Université Toulouse III -- Paul Sabatier) previously demonstrated. Now the same team of scientists has gone a step further, proving that a slime mold can transmit what it has learned to a fellow slime mold when the two combine. These new findings are published in the December 21, 2016, issue of the Proceedings of the Royal Society B.

Imagine you could temporarily fuse with someone, acquire that person's knowledge, and then split off to become your separate self again. With slime molds, that really happens! The slime mold -- Physarum polycephalum for scientists -- is a unicellular organism whose natural habitat is forest litter. But it can also be cultured in a laboratory petri dish. Audrey Dussutour and David Vogel had already trained slime molds to move past repellent but harmless substances (e.g. coffee, quinine, or salt) to reach their food. They now reveal that a slime mold that has learned to ignore salt can transmit this acquired behavior to another simply by fusing with it. ...
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FULL STORY: https://www.sciencedaily.com/releases/2016/12/161221090246.htm
 
INT21 said:
Multiple sexes ?
How many are they ?
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EnolaGaia said:
720.
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Here's some background, as discussed in an article about Le Blob ...

... On the subject of mating, did you know that slime molds have more than 720 sexes? It's true — thanks to some weird chromosomal alchemy.

In humans, sex is determined by the combination of chromosomes carried by a mating sperm cell and an ovule. A sperm cell can carry either an X or a Y chromosome, while an ovule will always carry a Y, resulting in a new cell with either XX chromosomes (a female) or XY chromosomes (a male).

For slime molds, things get a little… stickier. Instead of having just two types of sexual chromosomes (X or Y), a slime mold’s sex is determined by three different locations or "loci" on their chromosomes, each of which has many different alleles (or gene variations).

"To date, at least 16, 15 and 3 alleles are known to exist at each of the three loci," Audrey Dussutour, a slime mold researcher at the Research Centre on Animal Cognition of Toulouse University, told Live Science in an email. In other words, slime molds have 720 possible sex chromosome combinations. That's a lot — but luckily, two slime mold spores don’t need to have the same sexual type to mate. "To cross efficiently, spores must carry different alleles," Dussutour said.
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FULL STORY: https://www.livescience.com/paris-zoo-blob-slime-mold.html
 
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