Stages of mitosis

G1 phase

• Enter cell cycle or exit cell cycle (G0/quiescence)

• Depends on intrinsic signals (cell size)

• Depends on extrinsic signals (nutrients/ mitogens)

• Requires CycD/CDK4 or CDK6

• Most cells in your body have exited the cell cycle!

S phase

• Genome duplication

✴Once and only once per cell cycle

✴All or nothing •Requires S-CDK activity (CycE/CycA-CDK2)

• Centrioles are duplicated (centrosomes)

G2 Phase

• Ensure that DNA replication is complete

• Repair/resolve any DNA damage prior to mitosis

M Phase

• Chromosome segregation

• Requires M-CDK - CycB/CDK1

Prophase

• Duplicated chromosomes condense

• Mitotic spindle assembles

• Centrosomes move apart

Prometaphase

• Breakdown of the nuclear envelope

• Chromosomes attach to the mitotic spindle through the kinetochore

• Active movement of chromosomes

Metaphase

• Chromosomes align a the equator of the spindle

• Each sister chromatid is attached to opposite poles of the spindle

Anaphase

• Sister chromatids are pulled toward the spindle pole

• Kinetochore microtubules get shorter

• Spindles move outward

Telophase

• Chromosomes arrive at the spindle poles

• New nuclear envelope reassembles around each set of chromosomes

• Chromosomes begin to decondense

Cytokinesis

• Cytoplasm is divided in two by a contractile ring

• Two daughter cells are formed, each with one nucleus

Phases w/in interphase

G1, S, G2 (everything except M phase)