Some cells are meant to live, and some are meant to die. The linker cell of Caenorhabditis elegans, a tiny worm that is a favored model organism for biologists, is among those destined for termination. This cell helps determine the shape of the gonad in male worms--and then it dies, after two days, just as the worms are transitioning from larvae into adults. This programmed cell death is a normal part of the animal's development, yet the genetic and molecular mechanisms underpinning it have not been worked out. Scientists in Rockefeller University's Laboratory of Developmental Genetics, headed by Shai Shaham, had previously shown that the linker cell does not expire by apoptosis, a more commonly studied form of programmed cell death. "Everything about this death process is different from apoptosis," he says. "It looks different under the microscope, it requires different genes, and it has different kinetics."

Many ways for cells to die have been observed and described in the artificial milieu of a tissue culture dish, but not in a living organism. Now, the Shaham lab has been able to study the molecular mechanism that causes linker cell death in worms. Their findings, reported in eLife, suggest that the linker cell's newly discovered dying process resembles that which leads to the loss of neurons, or neuronal parts, in people with some neurodegenerative disorders.