Geckos can sever their tails along different points because they’re marked by “dotted lines,” a team of researchers has found.
When a predator pounces from behind, a lizard can voluntarily drop its tail and make a quick getaway while its attacker remains distracted by the amputated, still-wriggling appendage. But this evolutionary strategy comes with some disadvantages, too: For a lizard, a tail is a crucial balancing limb, a sign of social status and a store of fat reserves. (In fact, some species will return later to eat their own tail, probably to get that fat back, the authors write.)
But tails don’t all drop in the same places – many species can sever at different points (perhaps to minimize tail loss). Using an MRI machine, an electron microscope and a host of other tools, a team of researchers from Denmark decided to study the tokay gecko tail in-depth to see if they could discover the lizards’ secret.
They found that there are chains of cells along what appear to be severing points in the tail – chains that could act as a “cellular zipper,” the authors write, quickly separating the flesh on either side when a lizard tenses the right muscles.