Stress turns tiny worm into a big-mouthed cannibal

Among the soil-dwelling worms known as nematodes, Allodiplogaster sudhausi is already a bit of a monster. It’s about twice as large as its relatives—admittedly, only about the length of a fruit fly—the result of an ancient doubling of its genome . But when starved, it can become a real nightmare, researchers report in a bioRxiv preprint. The creature begins to resemble something out of Dune , growing a giant mouth and indiscriminately eating its kin —the only animal that regularly does so. When fed bacteria, other nematodes develop small mouths and are uninterested in eating other worms. When only given nematode larvae, however, their mouths grow larger and they gorge on the other worms — though, notably, not their own offspring . Hoping to re-create the phenomenon in A. sudhausi, researchers tried giving the worms all sorts of different foods. But they saw something strange when they fed the animals Penicillium camemberti , a fungus used to make camembert and other cheeses. On a fungal diet, the worm grew a giant mouth, a body shape the researchers dubbed the teratostomatous morph (teras being an ancient Greek word for monster). Other nematodes can’t do this. A. sudhausi’s extra set of genes could be key. It may be a response to stress. Fungi, it seems, are simply not nutritious enough for the creatures. The ability to monster out may g...
Source: ScienceNOW - Category: Science Source Type: news