Bumping an embryo’s cells can switch the direction of its spiral
This is a long way from working in politics. But for a snail, researchers report that just a little nudge of some early-dividing cells can push a youngster from left-leaning to right, or vice versa.
That nudge has to come when the Lymnaea stagnalis’ embryo’s first four cells split into eight, says Reiko Kuroda of the University of Tokyo, who studies chirality, or handedness. In nature, a single gene (not yet identified) acts in the mother snail to control which way offspring coil. Kuroda and her colleagues intervened in the usual development, using tiny glass rods to push four of the newly