摘要：

In the nematode C. elegans, cells undergoing programmed death in the developing ventral nerve cord were identified by Nomarski optics and prepared for ultrastructural study at various times after their birth in mitosis. The sequence of changes observed suggests that the hypodermis recognizes the dying cell before completion of telophase. The dying cell is engulfed and digestion then occurs until all that remains within the hypodermal cytoplasm is a collection of membranous whorls inter-spersed with condensed chromatin-like remnants. The process shares several features with apoptosis, the mode of programmed cell death observed in vertebrates and insects. The selection of cells for programmed death appears not to involve competition for peripheral targets.

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