Figure 1
From: Deadly dowry: how engulfment pathways promote cell killing
The engulfment pathways promote the killing of the NSM sister cell by contributing to the polarization of the NSM neuroblast, which is required for the unequal segregation of apoptotic potential. Left: Active CED-3 caspase present in the NSM neuroblast generates a ‘polarize-me signal’ (orange arrows). Middle: The ‘polarize-me signal’ induces the accumulation of the phagocytic receptor CED-1 mEGF10 on plasma membranes of neighbors that face the dorsal side of the NSM neuroblast. This accumulation leads to the activation of the two partially-redundant, parallel engulfment pathways in the two dorsal neighbors (indicated by orange shading). Right: NSM neuroblast at metaphase. The activities of the engulfment pathways in the dorsal neighbors generate a signal (blue arrows) that contributes to the polarization of the NSM neuroblast along the dorsal–ventral axis. This dorsal–ventral polarity is reflected in the gradient of active CED-3 caspase that is established and the differing amounts of peri-centriolar material (PCM) that is associated with the two centrosomes. As a result of this polarity ‘apoptotic potential’ (including active CED-3 caspase) is unequally segregated during NSM neuroblast division with the daughter that inherits the dorsal part of the NSM neuroblast (the NSM sister cell) inheriting more of apoptotic potential than the daughter that is formed from the ventral part (the NSM). See text for details
