Unformatted text preview: c bodies.
Apoptotic cells and cell fragments are efficiently recognized and phagocytosed by both macrophages and neighboring cells, so cells that die by
apoptosis are rapidly removed from tissues. In contrast, cells that die by
necrosis swell and lyse, releasing their contents into the extracellular space
and causing inflammation. The removal of apoptotic cells is mediated by
the expression of so-called “eat me” signals on the cell surface. These signals include phosphatidylserine, which is normally restricted to the inner
leaflet of the plasma membrane (see Figure 13.2). During apoptosis, phosphatidylserine becomes expressed on the cell surface where it is recognized
by receptors expressed by phagocytic cells (Figure 17.2).
Pioneering studies of programmed cell death during the development of
C. elegans provided the critical initial insights that led to understanding the
molecular mechanism of apoptosis. These studies in the laboratory of
Robert Horvitz initially identified three genes that play key roles in regulating and execu...
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