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Page 1 Cell Cycle - Regulation Institute of Lifelong Learning, University of Delhi 0 Lesson: Cell Cycle: Regulation Lesson Developer: Rama Sisodia College/ Department: Department of Botany, Maitreyi College, University of Delhi Page 2 Cell Cycle - Regulation Institute of Lifelong Learning, University of Delhi 0 Lesson: Cell Cycle: Regulation Lesson Developer: Rama Sisodia College/ Department: Department of Botany, Maitreyi College, University of Delhi Cell Cycle - Regulation Institute of Lifelong Learning, University of Delhi 1 Table of Contents Chapter: Cell Cycle - Regulation ? Introduction ? Cell cycle regulation by internal check points ? G1 check point ? G2 check point ? M check point ? Regulator molecules of the cell cycle ? Cyclin dependent kinases ? Identification ? Regulation ? Classes of Cdks and Cyclins ? Cdk regulation of M phase ? Extracellular signals ? Checkpoint control ? DNA damage induced check points ? Spindle assembly check point ? Regulation of meiosis ? Fertilization ? Summary ? Exercise/ Practice ? Glossary ? References/ Bibliography/ Further Readings Page 3 Cell Cycle - Regulation Institute of Lifelong Learning, University of Delhi 0 Lesson: Cell Cycle: Regulation Lesson Developer: Rama Sisodia College/ Department: Department of Botany, Maitreyi College, University of Delhi Cell Cycle - Regulation Institute of Lifelong Learning, University of Delhi 1 Table of Contents Chapter: Cell Cycle - Regulation ? Introduction ? Cell cycle regulation by internal check points ? G1 check point ? G2 check point ? M check point ? Regulator molecules of the cell cycle ? Cyclin dependent kinases ? Identification ? Regulation ? Classes of Cdks and Cyclins ? Cdk regulation of M phase ? Extracellular signals ? Checkpoint control ? DNA damage induced check points ? Spindle assembly check point ? Regulation of meiosis ? Fertilization ? Summary ? Exercise/ Practice ? Glossary ? References/ Bibliography/ Further Readings Cell Cycle - Regulation Institute of Lifelong Learning, University of Delhi 2 Introduction An understanding of the mechanisms that control cell cycle is important not only for basic biology but also since it underlies the basis of studying cancer- the uncontrolled proliferation of cells. The transition from one phase to other of the cell cycle is very well coordinated and is under the control of extracellular signals as well as certain internal signals. Cell cycle regulation by internal checkpoints The progression of the cell cycle is regulated by check points in response to specific signals. Figure: Cell cycle check points Source: http://setarosite.org/images/biobook_images/Checkpoints1.jpg ? G1 check point o Start a regulatory check point characterized in budding yeast Saccharomyces cerevisiae that occurs in G1 and controls the transition from G1 to S in response to signals like presence of nutrients, cell size and mating factors. Page 4 Cell Cycle - Regulation Institute of Lifelong Learning, University of Delhi 0 Lesson: Cell Cycle: Regulation Lesson Developer: Rama Sisodia College/ Department: Department of Botany, Maitreyi College, University of Delhi Cell Cycle - Regulation Institute of Lifelong Learning, University of Delhi 1 Table of Contents Chapter: Cell Cycle - Regulation ? Introduction ? Cell cycle regulation by internal check points ? G1 check point ? G2 check point ? M check point ? Regulator molecules of the cell cycle ? Cyclin dependent kinases ? Identification ? Regulation ? Classes of Cdks and Cyclins ? Cdk regulation of M phase ? Extracellular signals ? Checkpoint control ? DNA damage induced check points ? Spindle assembly check point ? Regulation of meiosis ? Fertilization ? Summary ? Exercise/ Practice ? Glossary ? References/ Bibliography/ Further Readings Cell Cycle - Regulation Institute of Lifelong Learning, University of Delhi 2 Introduction An understanding of the mechanisms that control cell cycle is important not only for basic biology but also since it underlies the basis of studying cancer- the uncontrolled proliferation of cells. The transition from one phase to other of the cell cycle is very well coordinated and is under the control of extracellular signals as well as certain internal signals. Cell cycle regulation by internal checkpoints The progression of the cell cycle is regulated by check points in response to specific signals. Figure: Cell cycle check points Source: http://setarosite.org/images/biobook_images/Checkpoints1.jpg ? G1 check point o Start a regulatory check point characterized in budding yeast Saccharomyces cerevisiae that occurs in G1 and controls the transition from G1 to S in response to signals like presence of nutrients, cell size and mating factors. Cell Cycle - Regulation Institute of Lifelong Learning, University of Delhi 3 Figure: Cell cycle regulation in Saccharomyces cerevisiae Source: http://commons.wikimedia.org/wiki/File:Ch14f5a.jpg ? Similarly in animal cells a restriction point regulates the progression of cell cycle from G1 to S phase is controlled by extracellular signals like growth regulators. When the required growth factors are present the cell cycle progresses beyond the restriction point into the S phase. However in the absence of appropriate growth factors the cells enter a quiescent stage- Go and remain metabolically active but stop dividing and have reduced size. On availability of suitable growth factor these regain their ability to divide and reenter the cell cycle. Figure: Regulation of cell cycle in animal cells in response to growth factors Source: http://upload.wikimedia.org/wikipedia/commons/c/c2/Ch14f6.jpg Page 5 Cell Cycle - Regulation Institute of Lifelong Learning, University of Delhi 0 Lesson: Cell Cycle: Regulation Lesson Developer: Rama Sisodia College/ Department: Department of Botany, Maitreyi College, University of Delhi Cell Cycle - Regulation Institute of Lifelong Learning, University of Delhi 1 Table of Contents Chapter: Cell Cycle - Regulation ? Introduction ? Cell cycle regulation by internal check points ? G1 check point ? G2 check point ? M check point ? Regulator molecules of the cell cycle ? Cyclin dependent kinases ? Identification ? Regulation ? Classes of Cdks and Cyclins ? Cdk regulation of M phase ? Extracellular signals ? Checkpoint control ? DNA damage induced check points ? Spindle assembly check point ? Regulation of meiosis ? Fertilization ? Summary ? Exercise/ Practice ? Glossary ? References/ Bibliography/ Further Readings Cell Cycle - Regulation Institute of Lifelong Learning, University of Delhi 2 Introduction An understanding of the mechanisms that control cell cycle is important not only for basic biology but also since it underlies the basis of studying cancer- the uncontrolled proliferation of cells. The transition from one phase to other of the cell cycle is very well coordinated and is under the control of extracellular signals as well as certain internal signals. Cell cycle regulation by internal checkpoints The progression of the cell cycle is regulated by check points in response to specific signals. Figure: Cell cycle check points Source: http://setarosite.org/images/biobook_images/Checkpoints1.jpg ? G1 check point o Start a regulatory check point characterized in budding yeast Saccharomyces cerevisiae that occurs in G1 and controls the transition from G1 to S in response to signals like presence of nutrients, cell size and mating factors. Cell Cycle - Regulation Institute of Lifelong Learning, University of Delhi 3 Figure: Cell cycle regulation in Saccharomyces cerevisiae Source: http://commons.wikimedia.org/wiki/File:Ch14f5a.jpg ? Similarly in animal cells a restriction point regulates the progression of cell cycle from G1 to S phase is controlled by extracellular signals like growth regulators. When the required growth factors are present the cell cycle progresses beyond the restriction point into the S phase. However in the absence of appropriate growth factors the cells enter a quiescent stage- Go and remain metabolically active but stop dividing and have reduced size. On availability of suitable growth factor these regain their ability to divide and reenter the cell cycle. Figure: Regulation of cell cycle in animal cells in response to growth factors Source: http://upload.wikimedia.org/wikipedia/commons/c/c2/Ch14f6.jpg Cell Cycle - Regulation Institute of Lifelong Learning, University of Delhi 4 ? G2 check point In contrast to these examples cell cycle is regulated by a check point that exists in the G2 phase and controls the progression into the M phase as seen in fission yeast Schizosaccharomyces pombe monitored by appropriate cell size and availability of nutrients. Similarly in vertebrate oocytes the control of cell cycle in G2 phase is seen in response to hormones and the cells remain arrested in G2 phase until triggered to divide. ? M check point A checkpoint exists at the end of the mitosis – the spindle assembly checkpoint that monitors the assembly and alignment of the spindle and therefore ensures that a complete set of chromosomes are distributed between the two newly formed daughter cells. In addition to these, several checkpoints in the G1, S, and G2 exist to ensure integrity of genome i.e. detect the presence of damaged and unreplicated DNA and coordinate the recruitment of repair machinery to these sites. Figure: The three main cell cycle checkpoints Source: ILLL Inhouse Animation: http://outreach.mcb.harvard.edu/animations/checkpoints.swf http://sites.sinauer.com/cooper5e/animation1603.html Regulator molecules of the cell cycleRead More
1. What is cell cycle regulation in botany? |
2. How is the cell cycle regulated in plants? |
3. What happens if cell cycle regulation is disrupted in plants? |
4. How do external factors influence cell cycle regulation in plants? |
5. Are there any similarities in cell cycle regulation between plants and animals? |
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