北京大学：《分子细胞生物学》课程教学资源（PPT课件讲稿，英文版）Chapter 11 Cell proliferation and its regulation

Chapter ll Cell proliferation and its regulation Significance I. For the growth and development of a multicellular organism, and for the generation of offspring 2. Produce new organisms in unicellular species 3. Renew the aging, apoptotic cells, and damaged tissue So, cell proliferation is one of the most important characters for life

Cell proliferation and its regulation Significance: 1. For the growth and development of a multicellular organism, and for the generation of offspring; 2. Produce new organisms in unicellular species; 3. Renew the aging, apoptotic cells, and damaged tissue; So, cell proliferation is one of the most important characters for life Chapter 11

If damaged seriously by UV, mouse will die within several days. /Direction of cell movement

If damaged seriously by UV, mouse will die within several days

1. The cell cycle A. Overview of the cell cycle The most basic function of the cell cycle is to duplicate accurately the vast amount of dNa in the chromosomes and then segregate the copies precisely into two genetically identical daughter cells mitosis metaphase-to-anaphase transition interphase prophase prometaphase metaphaseanaphasetel cophase INTERPHASE DNA replicati

1. The cell cycle A. Overview of the cell cycle The most basic function of the cell cycle is to duplicate accurately the vast amount of DNA in the chromosomes and then segregate the copies precisely into two genetically identical daughter cells

Cell cvcle phases: >Interphase: GI-S-G2 >M phase: Mitosis, Cytokinesis G:S Cel grows and DNA replication es out nomal and chromos metabolism; duplication 24 hours NTERPHASE

❖Cell cycle phases: ➢Interphase: G1 -S-G2 ➢M phase: Mitosis, Cytokinesis

o Different cell cycle length Some eukaryotic cell cycle times Cell Type Cell-Cycle Times Early frog embryo cells 30 minutes Yeast cells 1.5-3 hours Intestinal epithelial cells 12 hours Mammalian fibroblasts in culture -20 hours Human liver cells I year The greatest variation occurs in the duration of GI The shortest eukaryotic division cycles of all are the early embryonic cell cycles, no G and g2

❖ Different cell cycle length Some eukaryotic cell cycle times The greatest variation occurs in the duration of G1 The shortest eukaryotic division cycles of all are the early embryonic cell cycles, no G1 and G2

Biochemical events of cell cycle GI phase: Synthesize proteins(RNA) for the dNa replication. Uncondense chromatin sphase: Synthesis of DNa and histones G2 2 phase: Synthesis of a few proteins(rna) M phase: Mitosis and meiosis and cytokinesis Chromosome condense Mitotic spindle Contractile ring Two daughter cells

❖ Biochemical events of cell cycle G1 phase: Synthesize proteins (RNA) for the DNA replication. Uncondense chromatin. S phase: Synthesis of DNA and Histones G2 phase: Synthesis of a few proteins (RNA) M phase: Mitosis and meiosis and cytokinesis Two daughter cells Chromosome condense Mitotic spindle Contractile ring

M PHASE mitosis Inuclear division cytokinesis G PHASE (cytoplasmic divisionl INTERPHASE G G PHASE S PHASE (DNA replication OVERVEW OF THE CELL CYCLE

Three categories of cells in vivo (1)Cycling cells Dividing continuously--Stem cells ②2) Go cells appropriate stimulus: liver cells, lymphocyte en an Do not divide normally, but divide when gi 3 Terminally Differentiated cells Highly specialized, have lost the ability to divide until they die: muscle cells, red blood cells, nerve cells

❖ Three categories of cells in vivo (1)Cycling cells Dividing continuously—Stem cells (2) G0 cells Do not divide normally, but divide when given an appropriate stimulus: liver cells, lymphocytes (3) Terminally Differentiated cells Highly specialized, have lost the ability to divide until they die: muscle cells, red blood cells, nerve cells

Embryo cells Cycling GO Terminal cels cells cels

Embryo cells Cycling cells G0 cells Terminal cells