Printed mucus or mold mucus is an informal name given to some kind of unrelated eukaryotic organism that can live free as a single cell, but can gather together to form multicellular reproductive structures. Mucus molds were previously classified as mushrooms but are no longer considered part of the kingdom. Although not related to each other, they are sometimes still grouped for comfort in a paraphyletic group called the Protista kingdom.
More than 900 species of slime mold appear worldwide. Their common name refers to parts of some of the life cycles of these organisms where they can appear as "mucus" gelatin. This is mostly seen with myxogastria, which is the only macroscopic mucus mold. Most of the mold mucus is smaller than a few centimeters, but some species can reach sizes up to several square meters and masses up to 30 grams.
Many mucus fungi, especially the "cellular" slime mushrooms, do not spend most of their time in the state. During abundant food, these mucus fungi exist as single-celled organisms. When the food supply is lacking, many of these single-celled organisms get together and start moving as one body. Under these circumstances they are sensitive to chemicals in the air and can detect food sources. They can easily change the shape and function of parts and can form stems that produce fruit bodies, unleashing countless spores, light enough to carry winds or to ride on passing animals.
They feed on microorganisms that live in all types of dead plant material. They contribute to the decomposition of dead vegetation, and feed on bacteria, yeast, and fungi. For this reason, the mucus fungus is usually found in soil, grass, and on the forest floor, generally on leaf logs. However, in the tropics they are also common in inflorescences and fruits, and in air situations (eg, in tree canopies). In urban areas, they are found in mulch or even in leaf molds in rain gullies, and also grow in air conditioners, especially when the drains are clogged.
Video Slime mold
Taxonomy
Old classification
The slime mold, as a group, is polyphyletic. They were originally represented by subkingdom Gymnomycota in the Fungi kingdom and including the dead Myxomycota, Acrasiomycota and Labyrinthulomycota phyla. Today, the mucus fungus has been divided among some supergroups, none belonging to the Fungi kingdom.
Mucus molds can generally be divided into two main groups.
- Plasmodial mucus molds enclosed in a membrane without walls and is a large cell. This "supercell" (a syncytium) is essentially a cytoplasmic pouch containing thousands of individual nuclei. See heterokaryosis.
- In contrast, mobile mucus molds spend most of their lives as individual unicellular protists, but when chemical signals are secreted, they converge into clusters that act as one organism.
Modern classification
In more strict terms, the mucus mold consists of a mycetozoan group of amoebozoa. Mycetozoa includes the following three groups:
- Myxogastria or myxomycetes: syncronial, plasmodial, or acellular mucus mold
- Dictyosteliida or dictyostelids: cellular mucus mold
- Protosteloids
Even at this level of classification there is a conflict to be resolved. Recent molecular evidence suggests that, while the first two groups tend to be monophyletic, protosteloids tend to be polyphyletic. For this reason, scientists are currently trying to understand the relationships between these three groups.
The most commonly encountered is Myxogastria. The usual mucus mold that forms a small brown tufts on decayed wood is Stemonitis . Another form, which lives in decayed wood and is often used in research, is Physarum polycephalum . In logs, it has a yellow web-works appearance of yarn, up to several meters in size. Fuligo forms a yellow crust with mulch.
The Dictyosteliida , a cellular mucus fungus, is considerably associated with plasmodial mucus mold and has a very different lifestyle. Their amoebas do not form large coenocytes, and remain individualized. They live in the same habitat and feed on microorganisms. When the food runs out and they are ready to form sporangia, they do something very different. They release the signal molecules into their environment, where they find each other and create a flock. These amoebas then merge into small, multicellular-tailed multicellular creatures that crawl into a bright spot and grow into a fruitful body. Some amoeba become spores to start the next generation, but some amoeba sacrifice themselves to be dead stalks, lifting spores into the air.
The protosteloids have intermediate characters between the two previous groups, but they are much smaller, the fruit body only forms one to several spores.
Non-amozozoan mucus molds include:
- Acrasid (Acrasida Order): Mucus mold including Heterolobosea in Super Excavata group. They have a lifestyle similar to Dictyostelids, but their amoebae behaves differently, having eruptive pseudopodia. They used to belong to the dead Acrasiomycota phylum.
- Plasmodiophorids (Order of Plasmodiophorida): parasitic protists belonging to the super group of Rhizaria. They can cause cabbage root disease and scabby tuber disease. Plasmodiophorids also form coenocytes, but are internal parasites of plants (eg, Club root disease from cabbage).
- Labyrinthulomycota: the mucus net, which includes the superfilum Heterokonta as the Labyrinthulomycetes class. They are the sea and form a network of mazes where amoeba without pseudopods can travel.
- Fonticula is a cellular mucus mushroom that forms the body of a fruit in the form of a volcano. Fonticula is not closely related to Dictyosteliida or Acrasidae. A 2009 paper found it related to Nuclearia , which in turn is related to fungi.
Maps Slime mold
Life cycle
The mucus fungus starts life as an amoebic-like cell. These unicellular amoebae are generally haploid, and eat bacteria. These Amoebies can mate if they find the correct type of mating and form a zygote which then grows into plasmodia. It contains many nuclei without cell membranes between them, and can grow into meters in size. The species Fuligo septica is often seen as a slimy yellow tissue inside and on decayed wood. Amoebae and plasmodia ingest microorganisms. Plasmodium grows into an interconnected network of protoplasmic strands.
In each strand of protoplasm, the content of the cytoplasm flows rapidly. If one strand is carefully monitored for about 50 seconds, the cytoplasm may appear to slow down, stop, and then reverse. The streaming prototype of plasmodial strands can reach speeds of up to 1.35 mm per second, which is the fastest recorded rate for any microorganisms. Plasmodium migration is achieved when a larger protoplasm flow to advance the area and protoplasm is withdrawn from the back area. When the food supply is reduced, plasmodium will migrate to the surface of the substrate and transform into a rigid fruit body. The fruit body or sporangia is what we usually see; they may superficially look like mushrooms or fungi but are not associated with a true mushroom. This sporangia will then release the spores that hatch into amoeba to start the life cycle again.
Plasmodia
In Myxogastria , the plasmodial part of the life cycle occurs only after syngamy, which is a combination of the cytoplasm and nucleus myxoamoebae or swarm cells. The diploid zygote becomes a multinuclear plasmodium through various nuclear divisions without further cell division. Myxomycete plasmodia is a multinucleate mass of protoplasm that moves through the cytoplasmic stream. In order for plasmodium to move, the cytoplasm must be switched toward the front end of the left end. This process produces plasmodium forward in front of fan-like. As it moves, plasmodium also obtains nutrients through bacterial phagocytosis and small pieces of organic matter.
Plasmodium also has the ability to divide and form separate plasmodia. In contrast, separate plasmodia that are genetically similar and compatible can fuse together to create a larger plasmodium. If the condition becomes dry, plasmodium will form sclerotium, essentially dry and inactive state. If the condition is wet again, sclerotium absorbs water and the active plasmodium is restored. When food supply is reduced, Myxomycete plasmodium will enter the next stage of its life cycle to form haploid spores, often in well-defined sporangium or other spore bearing structures.
Behavior
When the mass or mounds of phlegm mushrooms are physically separated, the cells find their way back to reunite. The study of Physarum has even demonstrated the ability to learn and predict periodic unfavorable conditions in laboratory experiments. John Tyler Bonner, a professor of ecology known for his studies of the slime mold, argues that they are "nothing more than a bag of amoeba wrapped in a thin mucous membrane, but they manage to have the same behavioral behavior with animals that have muscles and nerves with ganglia - simple brain. "
Atsushi Tero from Hokkaido University grew the Physarum polycephalum slimy mushroom in a flat wet plate, placing the mold in a central position representing Tokyo and oat flakes around it in accordance with the location of other major cities in Greater Tokyo. Area. Like Physarum avoiding bright light, light is used to simulate mountains, water and other obstacles on the plate. The first solid mold fills the space with plasmodia, and then attenuates the network to focus on the branches that are connected efficiently. The network is very similar to the Tokyo train system.
See also
- Dictyostelium
- Mushroom, a fungus
- Mycetozoa
- Sorocarp
- Abundant motivation
- Water mold, or Oomycete, a kind of protista
References
External links
- Slime Mold Solve Maze Puzzle from abc.net.au
- Slime Mold doubles Rail Networks from The Economist
- Designing a highway by way of slime mold from New Scientist
- Hunting Slime Molds from Smithsonian Magazine
Source of the article : Wikipedia
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