细胞生物学第十二章 细胞增殖及其调控.pptx

1、,CELL BIOLOGY 邹 方 东,College of Life Science, SCU,细胞学说：,“Where a cell arises, there must be a previous cell, just as animals can only arise from animals and plants from plants.”,德国病理学家 威尔肖,Chapter 12,Cell proliferation and control 细胞增殖及调控,I. Significances,For the generation of offspring, and the grow

2、th and development of a multicellular organism,1.,6 weeks,12 weeks,16 weeks,Significances,2. Renew the aging, apoptotic cells, and damaged tissue,Red blood cell 120 d. 1011 / d,2 million stem cells divide every second,Damaged tissue by UV light,If damaged seriously by X-ray, mouse will die within se

3、veral days,II.The cell-division cycle,细胞分裂周期,1. Overview of the cell cycle,G1,S G2,Interphase间期 M phase分裂期,Cell cycle,Different cell cycle length,Some eukaryotic cell cycle times,Cell type,Cell-cycle time,Early frog embryo cells 30min Yeast cells 1.5-3h Intestinal epithelial cells 12h Human liver ce

4、lls 1 year,Why so different?,The greatest variation occurs in the duration of G1,小鼠食管上皮细胞 T=115h G1=103h 十二指肠上皮细胞 T=15h G1=6h,2. Three categories of cells in vivo,(1). Cycling cells,Dividing continuously ?,(2). G cells,0,Do not divide normally, but divide when stimulus:,liver cells, lymphocytes,(3).

5、Terminally Differentiated cells,Highly specialized, have lost the ability to divide until they die.,Embryo cells,Cycling G Terminal,0,cells,cells cells,?,How to study Cell cycle progression,z How can we tell what stage an animal cell has,reached in the cell cycle?,Observe with a mcroscope,BrdU-lable

6、d epithelia cells of the zebrafish gut. (Gree: S phase cells) phase cells),BrdU-labled RKO cells (Gree: S Dr. Zou FD,Measure the DNA content with a flow cytometer (fluorescent-activated cell sorter, FACS),G1 cells greater?,WT,KO,G1/S progression in RKO WT and miR-21 knockout cells,3. Synchronization

7、 of cell 细胞同步化,(1). Natural synchronization,Early embryo in most invertebrates and a few,vertebrates,果蝇胚胎,(2). Selected synchronization,M phase,Blocking DNA synthesis by TdR: G1/S,G1,G1/S,M,S,G2,Blocking cells in metaphase by 秋水酰素 ?,4. Special cell cycles Early embryo,30min / cell cycle,Frog Xenopus

8、 laevis,Why so rapidly?,No G1 and G2 phase, S phase is very short,Have little or no need to synthesize components other than DNA during cell division,1,2,3,4,III. M phase:,mitosis and cytokinesis,1. Mitosis (Nuclear division),Prophase,Prometaphase Metaphase Anaphase,Telophase,(1). Prophase,Formation

9、 of the compacted mitotic chromosome,Condensin 浓缩素,Vincent L. et al., Multiple roles of Condensins: a complex story, Biology of the Cell, 2004, 96: 201213,Activated M-Cdk phosphrylates condensin subunits, triggering the assembly of condensin complexes on DNA and condensation of the chromosome.,The c

10、ondensin can use energy of ATP hydtolysis to promote DNA coiling (in vitro).,Cohesin 粘连素,The sister chromatids are glued together by cohesins.,Formation of the mitotic spindle,Centrosome duplicated at S, and separate to form mitotic spindle at the beginning of prophase,Golgi, ER etc. disperse to for

11、m vesicles; kinetochore assembly,Aster MTs,interpolar MTs,(2). Prometaphase,Nuclear envelope breakdown Microtubules catch chromosomes,Microtubule behavior,Three classes of MT,(3). Metaphase,The pushing and pulling forces drive the chromosomes to the metaphase plate,(4). Anaphase,Chromatids separate

12、Migrate to spindle pole,Anaphase A:,The movement of the chromosomes toward the poles; Kinetochore MT disassemble at both ends during,anaphase A.,Anaphase B:,The two spindle poles move farther apart.,(5). Telophase,Chromosome Golgi, ER,Nuclear envelope Nucleus, Nucleolus,2. Cytokinesis (Cytoplasm div

13、ision),(1). In animal cells,蛙受精卵的卵裂,培养细胞的胞质分裂,Contractile ring 有丝分裂收缩环,Where the cleavage plane form?,The site of formation of the cleavage plane,(2). In plant cells,Summary,Two identical daughter cells,如何保证遗传物质准确分配给子细 胞？,3. Meiosis 减数分裂,Meiosis,Mitosis,III. Control of cell cycle,Cell-cycle control system safely guides the cell through the events of the cell cycle,In most eucaryotic cells, the ce