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Mitosis to Meiosis. Sept. 6, 2005. Centriole Dynamics. Mitosis. What happens in G1, S, G2? What is controlling the transitions? Explain how any process in the cell requires hundreds or thousands of genes.
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Mitosis to Meiosis Sept. 6, 2005
Centriole Dynamics
Mitosis • What happens in G1, S, G2? • What is controlling the transitions? • Explain how any process in the cellrequires hundreds or thousands of genes. • Give an example how timing of genes is as important as the products of the genes. • How does Metaphase “happen”? • How does Anaphase “happen”?
Cyclins and Cell Cycle Cell Cycle Model
Cell Cycle Controls • Cyclins (accelerators) • Kinases (breaks) • Hormones (initiators, inhibitors) • DNA replication process • DNA repair processes (p53 protein) • Microtubule (Spindle) processes
1995 Process Description 1960 ProcessDescription Mitosis
Functional Groups of Genes % of genome
Mitosis Cell Cycle Interphase G2 Interphase G1 Synthesis for mitosis House-keeping processes Cell differentiation House-keeping processes Interphase S Restriction Point 100’s to 1,000’s of sites initiate DNA replication
Chromosome “painting” with fluorescent antibodies specific for chromosome proteins characteristic of each homologus pair Polar view showing homologues in mitotic metaphase Nucleus
Initiation ofAnaphase (follows release of M-arrest)
Meiosis: Two Divisions • How does Meiosis I differ from Mitosis? • What kinds of regulatory systems would achieve the conversion of Mitosis into Meiosis I?