Cytological analysis of the mother cell death process during sporulation in Bacillus subtilis.

We have identified the following events during the late stage in the mother cell in Bacillus subtilis: spore detachment from the polar site of the mother cell, membrane rupture, cell wall collapse, and release of the free spore. The membrane rupture was followed by mother cell lysis. Moreover, we found that NucB, an extracellular nuclease, is involved in DNA degradation after mother cell lysis.