Embryoid bodies can't cavitate (top) if their cells don't eat themselves (bottom).
LEVINE/ELSEVIER
During embryonic development, the carving out of the body's shape requires a vast number of cells to be eliminated. Coincident with this large-scale programmed cell death, cells also perform autophagy, but whether this self-eating is required for normal embryogenesis was unclear.
To address this question, Qu et al. grew autophagy-deficient embryo-like structures in culture. These embryoid bodies normally develop internal cavities, but, in the absence of autophagy, the bodies remained solid.
The lack of cavitation was not due to a lack of programmed cell death but instead to a failure in clearance of the dead cells. Apoptotic cells normally express signals that tell waste disposal...