How does slime mould grow?

CellsRcool

http://www.newscientist.com/article/...mould-way.html

I watched a bbc programm about the decay of food. Slime mould was mention and they showed how when they layed out oat flakes in the pattern of major cities, it could link these in the shortest possible route. It did this by growing itself out. Above is a link to a new scientist article on this. So it grows. I always thought growing was essentially mitosis of cell. But it is and remain single celled, so mitosis has not occured. How does it grow out like this?

Biosyn

I thought slime mold was made up of more than one cell...multiple nuclei without cell membrane between them. All of the nuclei undergo mitosis simultaneously.

jim mcnamara

Biosyn is correct. Slime molds can actually move over surfaces by extension. Slime molds are a collective term. They actually have all kinds of taxonomic "issues", that other Eukaryota do not have, and are currently dumped into a tentative bin called Unikonta.

Slime molds have always been sort of "out there" and beyond our classification schemes. When I learned Myxomycota (old classification ) 50 years ago , they were considered fungi. Now they are protists and are kind of set off into their own little world.

They reproduce by creating zillions of sporangia, all at one time. Some "single cell" species mass together briefly into a multinucleate blob of protplasm to do this, then form sporangia. Other species spend most of their time as a big multinucleate glob, kinda like a super gigantic cell, as big as 20-30cm across. Then they sporulate. They are all over the place in moist temperate zones, most people don't know them when they see the larger ones. Some Fuligo species (another lumping ground) look like vomit. If you pull them apart, they will go back together, veeery slowly. If you do that too many times, they dry out, and become sporangia.

They live on saprophtyic bacteria that grow on decaying organic material.

They are all just cooler'n all get out. I love 'em.

Biosyn

I don't understand how this has anything to do with slime mold.

It's advertising some "Super Mineral" but the description is of an HTC phone. Hahaha...fail. In fact, the whole website you linked us is a failure.

Pythagorean

Pythagorean

There's a mathematical chemotaxis model for slime molds that I've always found interesting in terms of the dynamics: the solutions can decay from chaotic into both periodic and homogenous.

http://www.sciencedirect.com/science...67278910002617

Spatio-temporal chaos in a chemotaxis model
Kevin J. Paintera, Thomas Hillenb
Physica D: Nonlinear Phenomena
Volume 240, Issues 4–5, 15 February 2011, Pages 363–375

~I guess it's supposed to be a more general chemotaxis model. Not sure why I equated it to slime molds in my memory, maybe the behavior of aggregating cell bodies?

~~ok, it does mention slime molds, just by latin name!

CellsRcool

So slime mould is single celled, but never really encountered as a single organism? they always link together into a community. Is my understanding now correct?

B.Spinoza

The other guys are right about the nature of the slime-moulds. IF you are asking also about how the mould manages to find the shortest route between 'oat-flake-cities' then I would imagine the following:

- a very simple set of instructions would be enough information to enable an efficient route.
- the branching patterns that link our cities, brain neurons, ant and fungi colonies are all governed by the same 'simple' -as in low information- rules.

Stephen Wolfram and Benoît Mandelbrot have done much work on how complexity can evolve from simple rules/algorithms, I seem to remember a good TED Talk on this.

Slime moulds are incredible organisms, I wonder if the mechanism that SM's use to re-group after being separated is the same/similar to that of choanoflagellates - sponges and the likes - you can put a sponge through a sieve and it will re-form into a branching colony.

Does anybody know much about the mechanisms behind these organisms ability to purposefully re-form into colonies?

I also wonder - after watching that b+w clip on the SM's I realised that they specialise in function when they act as a colony, to become part of a stalk or whatever. Surely this is on the way to a more complex organism? There may be little evolutionary pressure for the SM's to change their lifestyle, but I wonder how far back we have to go to find the last common ancestor of humans/choanoflagellates/slime moulds? I'm sure its billions of years or there abouts...

Experiment? Could we apply evolutionary pressure to a sponge and encourage it to evolve specialist cells instead of being a clone colony? They do this with vats of bacteria and force them to adapt to the available nutrients/Ph whatever.

To me slime moulds, choanoflagellates, echinoderms and cephalopods are some of the most interesting organisms I've heard of. If anybody has good suggestions as to where I can learn more accurate information from, please do share.

Thanks.