Cell death programmed in uninduced metanephric mesenchymal cells.

Metanephric mesenchyme may be converted to epithelia by the uteric bud (in vivo) and the spinal cord (in vitro). In their absence, the uniduced cells die or disappear. Morphological data, both in vitro and vivo, suggest that the demise of these cells is brought about by apoptosis, programmed cell death. By measuring DNA fragmentation in induced and uniduced cells, this study confirms not only that apoptosis occurs in the absence of an inducer, but also suggests that rescue from this process may be an important step in kidney development.