Slimy, Weird, Cheaters

Lurking in gutters, gardens and forests, just under-foot, lies something strange. Something almost alien. They lead independent lives as single cells foraging for, and feeding on, bacteria. But when food becomes scarce they work together, in their millions, forming a multicellular ‘organism’ of individuals. In this form they’re more mobile; moving about, looking for food or new environments, displaying something akin to a brainless form of intelligence. They are everywhere, on almost every continent; but they didn’t arrive on a meteorite, like aliens bent on world domination. Instead they’ve been with us for nearly a billion years. They are the ‘slime moulds’. But wherever individuals cooperate for the greater good of their ilk, there are always cheaters; even among the slime moulds.

Cholera’s Spring Loaded Nano-dagger

Bacteria have a number of tools to fend off foes or attack competitors, but now a new method can be added to the list: a spring-loaded dagger Research published in Nature by scientists at the Harvard Medical School and the California Institute of Technology investigated the structure of a mechanism used by the bacteria vibrio cholera to kill both competing bacteria and human cells, called the Type VI Secretary System (T6SS) in the cholera bacterium. It’s known that T6SS can deliver toxic proteins into nearby cells, but until now the exact mechanism was not known; now it appears T6SS could be using a poison tipped dagger to deliver this killing blow. “People aren’t surprised that animals have really interesting ways to hurt each other – snakes have venom, bears have claws,” says Grant Jensen, professor of biology at Caltech and co-leader of the study. “But they might be surprised that ...(Read More)