第1章__绪论细胞生物学(翟中和第四版)摘要.pptVIP

* 图片来源：/cells/nucleus/chromatin.html * 图片来源：/nrm/journal/v5/n4/fig_tab/nrm1358_F2.html Controlled cell death, plant survival and development. Nature Reviews Molecular Cell Biology 5, 305-315 (April 2004) a | In the hypersensitive response, chromatin condensation and DNA cleavage into 50-kb fragments were observed before the apparent disruption of the vacuole, which takes places during the late stages of cell death18. Blebbing of the vacuole and plasma membranes, and late destruction of organelles were also observed. At the final stage of this cell-death process, the plasma membrane collapses and separates from the cell wall18, 19, ending with the leakage of the dead cells content into the apoplast Fragmented nuclear DNA is shown throughout the figure as irregular, brown masses in the nuclei that are undergoing cell death. b | During the differentiation of tracheary elements, vacuole swelling and rupture is coordinated with the thickening and restructuring of the cell wall. The final collapse of the vacuole immediately precedes nuclear DNA fragmentation, which occurs at the late stages of the cell-death process before the final autolysis of the cell. Short stubbles on differentiating tracheary elements indicate reticulated secondary cell walls. Broken areas in the cell wall of terminally differentiated tracheary elements indicate spatially localized perforations. c | Apoptosis in animal cells initiates morphologically with chromatin condensation and fragmentation. Plasma-membrane ruffling is followed by the formation of apoptotic bodies from the repackaging of the cell content and their final engulfment by neighbouring cells or macrophages. * 图片来源：/nrm/journal/v8/n9/fig_tab/nrm2233_F1.html Cellular senescence: when bad things happen to good cells. Nature Reviews Molecular Cell Biology 8, 729-740 (September 2007) /doi/abs/10.1146/annurev-chembioeng-061010-114105?journalCode=chembioeng * * * * The key to every biological problem must finally be sought in the cell,