细胞分裂增殖教材分析.ppt

Masui and Markert’s experiments (J. Exp. Zool. 177:142, 1971) 注射实验表明：孕酮诱导卵母细胞成熟； 成熟卵细胞质中，含有卵母细胞成熟的因子，称做MPF。 MPF 的活性与细胞周期的关系 In the mid-1970s as a postdoc studying the fission yeast S. pombe. Nurse found cdc2 裂殖酵母中几个温度敏感的 cdc基因的隐性突变使得裂殖 酵母在周期中不能进入M期, 由于生长没有停止, 所以比正常的酵母长很多。 这些基因中的一个显性突变, 命名为 cdc2 。 cdc2D Normal cdc2- Cdc2 encodes a protein kinase with 34kD whose activity is required for cells to enter M phase.(p34cdc2) MPF是一种使多种底物蛋白磷酸化的蛋白激酶； 由M期Cyclin-Cdk(Cyclin-dependent protein kinase)形成的复合物。 MPF=CDK1=p34cdc2+cyclinB In 1982, Nurse and his colleagues found that CDC2 was identical in function to CDC28 from budding yeast, S. cerevisiae Hartwell found cdc28 Tim Hunt found cyclin in 1983 When the gel was developed on Friday 23 July 1982, I found that the strongest band early on suddenly got very much weaker at about the time when the eggs were about to divide in two. This was a stunning, startling discovery.“ 35S-Met: Fertilized eggs From Tim and his colleagues 16 min 60 min 80 min 120 min Cyclin: in sea urchin eggs that is destroyed at each cleavage division. Cell 33:389-396, 1983 What is the relationship between cyclins or cdc2 and MPF? MPF purification: 1988 (Xenopus egg) MPF=32kD+45kD MPF has protein kinase activity Cdc2 Antibody Cyclin B M phase Cyclin-Cdk (MPF) (Cyclin-dependent protein kinase) Cohesin 粘连素 The sister chromatids are glued together by cohesins. Aster MTs interpolar MTs 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 form vesicles; kinetochore assembly (2). 前中期Prometaphase 核膜破裂成小的膜泡，这一过程是由核纤层蛋白磷酸化导致核纤层解体 纺锤体微管与染色体的动粒结合，捕捉住染色体每个已复制的染色体有两个动粒，朝相反方向，保证与两极的微管结合； 纺锤体微管捕捉住染色体后，形成三种类型的微管 (3). 中期Metaphase 所有染色体排列到赤道板(Metaphase Plate) 上，标志着细胞分裂已进入中期 (4). 后期Anaphase 排列在赤道面上的染色体的姐妹染色单体 分离产生向极运动 Anaphase A: 后期A， 动粒微管去 装配变短， 染色体产生 两极运动 Anaphase B: 极间微管长度增加， 两极之间的距离逐 渐拉长，介导染色 体向极运动 (5). 末期Telophase ◆染色单体到达两极，即进入了末期（telophase