slemsvampsliv

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Detta är kungen inom slemsvampsforskningen, John Bonner!!!

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Where others see dirt, John Bonner sees beauty.
Where others see jumbled clumps, he sees highly sophisticated organization.
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At age 89, Bonner, the George M. Moffett Professor Emeritus ofBiology, is one of the world's leading experts on cellular slime molds, found in soils the world over. He has led the way in making "Dictyostelium discoideum" a model organism central to examining some of the major questions in experimental biology. Science magazine describes him as "the current patriarch of the slime mold community.”
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He has made them the subject of his latest book -- his 18th -- called "The Social Amoebae: The Biology of Cellular Slime Molds." Published by Princeton University Press, it gives a detailed history of his "beloved slime molds," showing where they fit into biology and how they may illuminate that vast subject. He intends it as "an essay on the big things we have learned.”
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What is it about this slimy, ground-dwelling critter that has captivated Bonner for nearly 70 years? 
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Slime molds are "no more than a bag of amoebae encased in a thin slime sheath," Bonner said. "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.”
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But they are not animals, or fungi, bacteria or plants. They belong to the fifth kingdom of life, the one least understood by scientists, known as Protists.

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Bonner likes to point out that slime molds possess a fascinating repertoire of behaviors. They can be chopped in two and reconstitute two versions of themselves. They exhibit a form of intelligence: When separated, they will put themselves back together and start to move. They avoid dead ends and are oriented by gases, such as oxygen. 
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Their life cycle intrigues researchers for the questions it raises about altruism. As the individual cells of Dictyostelium divide in two, their population doubles in a few hours. Once they have consumed all of their favorite food -- all the bacteria in the vicinity -- they will begin to gather at a central collection point. So many come together that the clumped cells become visible to the naked eye.

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From there, the cells dance a ballet. A 1984 BBC documentary, "Professor Bonner and the Slime Molds," took advantage of this natural choreography. The cells' motions are sped up on film and set to classical music. As they gather, they lengthen and attach to another, like a great conga line. A nipple forms on the clump, causing the mass to stretch out into a slug which then slowly inches along the Petri dish. A half day later, the slug, made up of hundreds of thousands of cells, will form what Bonner describes as a "fruiting body," a dead stalk with a ball of live spores on the top. Out of the lab and in the natural world, the spores will poke thorough soil and be carried away to new pastures by crawling insects and worms.
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The main value of the self-sacrifice by the stalk cells, scientists believe, is to maximize the spread of the organism. Sticking up into the air, it turns out, makes spore dispersal more effective. How is it that some cells are willing to be part of the stalk and die, so that some others may live on as spores? As Bonner has pointed out, this occurs because all of the cells are closely related genetically, and the lost genes of the stalk cells are carried on to the next generation by the spores. Experiments have shown that mixtures of species will separate and sort themselves out. It is as if they know their own kind.
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Between their seeming altruism and their other complex behavior, the slime molds raise compelling questions for scientists to ponder. After all this time, Bonner believes he has yet to get to the bottom of it all.