Editing Slime mold (section)

== Study ==

=== Use in research and teaching ===

The practical study of slime molds was facilitated by the introduction of the "moist culture chamber" by H. C. Gilbert and [[George Willard Martin|G. W. Martin]] in 1933.<ref>{{cite journal |last1=Gilbert |first1=H. C. |last2=Martin |first2=G. W. |author2-link=George Willard Martin |year=1933 |title=Myxomycetes found on the bark of living trees |journal=University of Iowa Studies in Natural History |volume=15 |pages=3–8}}</ref> Slime molds can be used to teach [[convergent evolution]], as the habit of forming a stalk with a sporangium that can release spores into the air, off the ground, has evolved repeatedly, such as in myxogastria (eukaryotes) and in myxobacteria ([[prokaryote]]s).<ref name="Keller Everhart 2010">{{cite journal |last1=Keller |first1=Harold W. |last2=Everhart |first2=Sydney |title=Importance of Myxomycetes in Biological Research and Teaching |journal=Fungi |date=2010 |volume=3 |issue=1 (Winter 2010)}}</ref> Further, both the (macroscopic) dictyostelids and the (microscopic) protostelids have a phase with motile amoebae and a phase with a stalk; in the protostelids, the stalk is tiny, supporting just one spore, but the logic of airborne spore dispersal is the same.<ref name="Keller Everhart 2010"/>

[[O'Neil Ray Collins|O. R. Collins]] showed that the slime mold ''[[Didymium (slime mold)|Didymium iridis]]'' had two strains (+ and −) of cells<!-- (heterothallism)-->, equivalent to gametes, that these could form [[immortalised cell line|immortal cell lines]] in [[microbiological culture|culture]], and that the system was controlled by [[allele]]s of a single gene. This made the species a [[model organism]] for exploring incompatibility, asexual reproduction, and mating types.<ref name="Keller Everhart 2010"/>

=== Biochemicals ===

Slime molds have been studied for their production of unusual organic compounds, including [[pigment]]s, [[antibiotic]]s, and [[anti-cancer drug]]s.<ref name="Keller Everhart 2010"/> Pigments include [[naphthoquinone]]s, physarochrome A, and compounds of tetramic acid. [[Bisindolylmaleimide]]s produced by ''Arcyria denudata'' include some [[Phosphorescence|phosphorescent]] compounds.<ref name="Steglich 1989">{{cite journal |last=Steglich |first=W. |title=Slime moulds (Myxomycetes) as a source of new biologically active metabolites |journal=Pure and Applied Chemistry |publisher=Walter de Gruyter GmbH |volume=61 |issue=3 |date=1 January 1989 |issn=1365-3075 |doi=10.1351/pac198961030281 |pages=281–288|s2cid=53663356 |doi-access=free }}</ref> The sporophores (fruiting bodies) of ''Arcyria denudata'' are colored red by arcyriaflavins A–C, which contain an unusual indolo[2,3-''a''][[carbazole]] [[alkaloid]] ring.<ref name="Dembitsky Řezanka Spížek Hanuš 2005">{{cite journal |last1=Dembitsky |first1=Valery M. |last2=Řezanka |first2=Tomáš |last3=Spížek |first3=Jaroslav |last4=Hanuš |first4=Lumír O. |title=Secondary metabolites of slime molds (myxomycetes) |journal=Phytochemistry |publisher=Elsevier BV |volume=66 |issue=7 |year=2005 |issn=0031-9422 |doi=10.1016/j.phytochem.2005.02.017 |pages=747–769|pmid=15797602 |bibcode=2005PChem..66..747D }}</ref> By 2022, more than 100 pigments had been isolated from slime molds, mostly from sporophores. It has been suggested that the many yellow-to-red pigments might be useful in [[cosmetics]].<ref name="Stoyneva-Gärtner Uzunov Androv Ivanov 2022">{{cite journal |last1=Stoyneva-Gärtner |first1=Maya |last2=Uzunov |first2=Blagoy |last3=Androv |first3=Miroslav |last4=Ivanov |first4=Kristian |last5=Gärtner |first5=Georg |title=Potential of Slime Molds as a Novel Source for the Cosmetics Industry |journal=Cosmetics |publisher=MDPI AG |volume=10 |issue=1 |date=21 December 2022 |issn=2079-9284 |doi=10.3390/cosmetics10010003 |page=3 |doi-access=free }}</ref> Some 42% of patients with [[seasonal allergic rhinitis]] reacted to myxogastrian spores, so the spores may contribute significantly as airborne [[allergen]]s.<ref name="Lierl 2013">{{cite journal |last=Lierl |first=Michelle B. |title=Myxomycete (slime mold) spores: unrecognized aeroallergens? |journal=Annals of Allergy, Asthma & Immunology |publisher=Elsevier BV |volume=111 |issue=6 |year=2013 |issn=1081-1206 |doi=10.1016/j.anai.2013.08.007 |pages=537–541.e2|pmid=24267365 }}</ref>

=== Computation ===

Slime molds share some similarities with neural systems in animals.<ref>{{cite book|last=Carr |first=William E. S. |chapter=Chemical Signaling Systems in Lower Organisms: A Prelude to the Evolution of Chemical Communication in the Nervous System |date=1989 |title=Evolution of the First Nervous Systems |pages=81–94 |editor-last=Anderson |editor-first=Peter A.V. |place=Boston, MA |publisher=Springer |doi=10.1007/978-1-4899-0921-3_6 |isbn=978-1-4899-0921-3 }}</ref> The membranes of both slime molds and neural cells contain receptor sites, which alter electrical properties of the membrane when it is bound.<ref>{{cite journal |last1=Carr |first1=William E. S. |last2=Gleeson |first2=Richard A. |last3=Trapido-Rosenthal |first3=Henry G. |title=The role of perireceptor events in chemosensory processes |journal=Trends in Neurosciences |volume=13 |issue=6 |pages=212–215 |date=June 1990 |pmid=1694326 |doi=10.1016/0166-2236(90)90162-4 |s2cid=46452914 }}</ref> Therefore, some studies on the early evolution of animal neural systems are inspired by slime molds.<ref>{{cite journal |last1=Lindsey |first1=J. |last2=Lasker |first2=R. |title=Chemical Signals in the Sea: Marine Allelochemics and Evolution. |journal=Fishery Bulletin |date=1974 |volume=72 |issue=1 |pages=1–11 |url=https://books.google.com/books?id=51xy60-M3jUC&dq=Kittredge+et+al.+slime+mold&pg=PA1 }}</ref><ref>{{cite journal |last1=Lenhoff |first1=H M |last2=Heagy |first2=W |title=Aquatic invertebrates: model systems for study of receptor activation and evolution of receptor proteins |journal=Annual Review of Pharmacology and Toxicology |volume=17 |issue=1 |pages=243–258 |date=April 1977 |pmid=17353 |doi=10.1146/annurev.pa.17.040177.001331 }}</ref><ref>{{cite journal |last1=Janssens |first1=P.M. |last2=Van Haastert |first2=P.J. |title=Molecular basis of transmembrane signal transduction in ''Dictyostelium discoideum'' |journal=Microbiological Reviews |volume=51 |issue=4 |pages=396–418 |date=December 1987 |pmid=2893972 |pmc=373123 |doi=10.1128/mr.51.4.396-418.1987 }}</ref> When a slime mold mass or mound is physically separated, the cells find their way back to re-unite. Studies on ''[[Physarum polycephalum]]'' have even shown the organism to have an ability to learn and predict periodic unfavorable conditions in laboratory experiments.<ref>{{cite journal |last1=Saigusa |first1=Tetsu |last2=Tero |first2=Atsushi |last3=Nakagaki |first3=Toshiyuki |last4=Kuramoto |first4=Yoshiki |title=Amoebae anticipate periodic events |journal=Physical Review Letters |volume=100 |issue=1 |pages=018101 |date=January 2008 |pmid=18232821 |doi=10.1103/PhysRevLett.100.018101 |hdl-access=free |bibcode=2008PhRvL.100a8101S |hdl=2115/33004 |s2cid=14710241 }}
* {{cite magazine |last=Barone |first=Jennifer |date=December 9, 2008 |title=#71: Slime Molds Show Surprising Degree of Intelligence |magazine=[[Discover (magazine)|Discover]] |url=http://discovermagazine.com/2009/jan/071|archive-date=December 10, 2008|archive-url=https://web.archive.org/web/20081210234929/http://discovermagazine.com/2009/jan/071}}</ref> [[John Tyler Bonner]], a professor of ecology known for his studies of slime molds, argues that they are "no more than a bag of amoebae encased in a thin slime sheath, yet they manage to have various behaviors that are equal to those of animals who possess muscles and nerves with ganglia – that is, simple brains."<ref>{{cite news |last1=MacPherson |first1=Kitta |date=January 21, 2010 |title=The 'sultan of slime': Biologist continues to be fascinated by organisms after nearly 70 years of study |url=https://www.princeton.edu/main/news/archive/S26/40/89S11/index.xml |publisher=Princeton University}}</ref>

The slime mold [[algorithm]] is a [[Heuristic (computer science)|meta-heuristic algorithm]], based on the behavior of aggregated slime molds as they stream in search of food. It is described as a simple, efficient, and flexible way of solving [[optimization problem]]s, such as finding the [[Shortest path problem|shortest path]] between [[Node (networking)|nodes]] in a network. However, it can become trapped in a [[local optimum]].<ref>{{cite journal |last1=Zheng |first1=Rong |author2=Jia, Heming |author3=Aualigah, Laith |author4=Liu, Qingxin |author5=Wang, Shuang |title=Deep ensemble of slime mold algorithm and arithmetic optimization algorithm for global optimization |journal=Processes |volume=9 |issue=10 |year=2021 |page=1774 |doi=10.3390/pr9101774 |url=https://www.mdpi.com/2227-9717/9/10/1774/pdf |doi-access=free }}</ref>

[[Toshiyuki Nakagaki]] and colleagues studied slime molds and their abilities to solve mazes by placing nodes at two points separated by a maze of plastic film. The mold explored all possible paths and solved it for the shortest path.<ref>{{Cite journal|url=https://www.nature.com/articles/35035159|journal=Nature|title=Maze-solving by an amoeboid organism|date=September 28, 2000|first1=Toshiyuki|last1=Nakagaki|first2=Hiroyasu|last2=Yamada|first3=Agotha|last3=Toth|volume=407 |issue=6803 |page=470 |doi=10.1038/35035159 |pmid=11028990 }}</ref>

=== Traffic system inspirations ===

[[File:Physarum polycephalum network.jpg|thumb|''Physarum polycephalum'' network grown in a period of 26 hours (6 stages shown) to simulate greater [[Tokyo]]'s rail network<ref name="Tero Takagi Saigusa Ito 2010"/>]]

[[Atsushi Tero]] and colleagues grew ''Physarum'' in a flat wet dish, placing the mold in a central position representing Tokyo, and oat flakes surrounding it corresponding to the locations of other major cities in the Greater Tokyo Area. As ''Physarum'' avoids bright light, light was used to simulate mountains, water and other obstacles in the dish. The mold first densely filled the space with plasmodia, and then thinned the network to focus on efficiently connected branches. The network closely resembled [[Tokyo subway|Tokyo's rail system]].<ref name="Tero Takagi Saigusa Ito 2010">{{cite journal |last1=Tero |first1=A. |last2=Takagi |first2=S. |last3=Saigusa |first3=T. |last4=Ito |first4=K. |last5=Bebber |first5=D.P. |last6=Fricker |first6=M.D. |last7=Yumiki |first7=K. |last8=Kobayashi |first8=R. |last9=Nakagaki |first9=T. |display-authors=3 |title=Rules for biologically inspired adaptive network design |journal=Science |volume=327 |issue=5964 |pages=439–442 |date=January 2010 |pmid=20093467 |doi=10.1126/science.1177894 |url=http://wiki.cs.unm.edu/pibbs/lib/exe/fetch.php?media=slimemold.pdf |s2cid=5001773 |bibcode=2010Sci...327..439T |archive-url=https://web.archive.org/web/20130421004038/http://wiki.cs.unm.edu/pibbs/lib/exe/fetch.php?media=slimemold.pdf |archive-date=2013-04-21 }}
* {{cite web |last=Yong |first=Ed |date=January 21, 2010 |title=Slime mould attacks simulates Tokyo rail network |website=ScienceBlogs |url=http://scienceblogs.com/notrocketscience/2010/01/21/slime-mould-attacks-simulates-tokyo-rail-network/}}</ref><ref>{{cite web |vauthors=Christiansen B |work=Technovelgy |url=http://www.technovelgy.com/ct/Science-Fiction-News.asp?NewsNum=2756 |title=Slime Mold Network Engineering |date=25 January 2010 }}</ref> ''P. polycephalum'' was used in experimental laboratory approximations of motorway networks of 14 geographical areas: Australia, Africa, Belgium, Brazil, Canada, China, Germany, Iberia, Italy, Malaysia, Mexico, the Netherlands, UK and US.<ref>{{cite web |last=Marks |first=P. |work=New Scientist |url=https://www.newscientist.com/article/mg20527426-300-designing-highways-the-slime-mould-way/ |title=Designing highways the slime mould way |date=6 January 2010 }}</ref><ref>{{cite journal|last1=Adamatzky |first1=Andrew |author1-link=Andrew Adamatzky |last2=Akl |first2=S. |last3=Alonso-Sanz |first3=R. |last4=van Dessel |first4=W. |last5=Ibrahim |first5=Z. |last6=Ilachinski |first6=A. |last7=Jones |first7=J. |last8=Kayem|first8=A.V.D.M. |last9=Martinez |first9=G.J. |last10=de Oliveira |first10=P. |last11=Prokopenko |first11=M. |last12=Schubert |first12=T. |last13=Sloot |first13=P. |last14=Strano |first14=E. |last15=Yang |first15=X.-S. |display-authors=3 |title=Are motorways rational from slime mould's point of view? |journal=International Journal of Parallel, Emergent and Distributed Systems |year=2013 |volume=28|issue=3 |pages=230–248 |doi=10.1080/17445760.2012.685884 |arxiv=1203.2851 |s2cid=15534238 }}</ref><ref>{{cite news |last=Parr |first=D. |newspaper=[[The Guardian]] |url=https://www.theguardian.com/cities/2014/feb/18/slime-mould-rail-road-transport-routes |title=Cities in motion: how slime mould can redraw our rail and road maps |date=18 February 2014 }}</ref> The filamentary structure of ''P. polycephalum'' forming a network to food sources is similar to the large scale [[galaxy filament]] structure of the [[universe]]. This observation has led astronomers to use simulations based on the behaviour of slime molds to inform their search for [[dark matter]].<ref>{{cite web|url=https://www.nasa.gov/feature/goddard/2020/slime-mold-simulations-used-to-map-dark-matter-holding-universe-together |title=Slime Mold Simulations Used to Map Dark Matter |work=NASA |date=10 March 2020}}</ref><ref>{{cite web |last=Wenz |first=J. |date=12 March 2020 |url=https://astronomy.com/news/2020/03/slime-mold-helps-astronomers-map-the-universes-dark-matter|title=Slime mold helps astronomers map dark matter |work=Astronomy magazine }}</ref>

=== Used as food ===

In central Mexico, the [[false puffball]] ''Enteridium lycoperdon'' was traditionally used as food; it was one of the species which mushroom-collectors or ''hongueros'' gathered on trips into the forest in the rainy season. One of its local names is "cheese mushroom", so called for its texture and flavor when cooked. It was salted, wrapped in a [[maize]] leaf, and baked in the ashes of a campfire; or boiled and eaten with maize [[tortilla]]s. ''Fuligo septica'' was similarly collected in Mexico, cooked with onions and peppers and eaten in a tortilla. In Ecuador, ''Lycogala epidendrum'' was called "yakich" and eaten raw as an appetizer.<ref name="Requejo Andres-Rodriguez 2019">{{cite journal |last1=Requejo  |first1=Oscar |last2=Andres-Rodriguez |first2=N. Floro |title=Consideraciones Etnobiologicas sobre los Mixomicetos |trans-title=Ethnobiological Considerations on Myxomycetes |journal=Bol. Soc. Micol. Madrid |volume=43 |date=2019 |pages=25–37 |url=https://www.researchgate.net/publication/339201976 |language=es}}</ref>

=== In popular culture ===

Oscar Requejo and N. Floro Andres-Rodriguez suggest that ''Fuligo septica'' may have inspired [[Irvin Yeaworth]]'s 1958 film ''[[The Blob]]'', in which a giant amoeba from space sets about engulfing people in a small American town.<ref name="Requejo Andres-Rodriguez 2019"/>