During the early developmental stages of vertebrates—animals that have a backbone and spinal column, including humans—cells undergo extensive rearrangements, and some cells migrate over large distances to populate particular areas and assume novel roles as differentiated cell types. Understanding how and when such cells switch their purpose in an embryo is an important and complex goal for developmental biologists. A recent study, led by researchers at the California Institute of Technology (Caltech), provides new clues about this process—at least in the case of neural crest cells, which give rise to most of the peripheral nervous system, to pigment cells, and to large portions of the facial skeleton.

Lurking in the crevices of our planet are millions and millions of microscopic worms. They live in soil, plants, water, ice, wildlife, and sometimes even humans.

At any given moment, millions of cells are on the move in the human body, typically on their way to aid in immune response, make repairs, or provide some other benefit to the structures around them. When the migration process goes wrong, however, the results can include tumor formation and metastatic cancer. Little has been known about how cell migration actually works, but now, with the help of some tiny worms, researchers at the California Institute of Technology (Caltech) have gained new insight into this highly complex task.