A G2 cell is fused with an M-phase cell. The G2 nucleus undergoes premature chromosome condensation.
Which factor in the M-phase cell is responsible?
- A
DNA polymerase
- B
Tubulin
- C
p53
- Dcheck_circle
MPF (M-phase/maturation-promoting factor; cyclin B-CDK1)
Explanation
Active MPF (cyclin B-CDK1) phosphorylates condensins, lamins, and other substrates to drive mitotic entry. Its presence in the M-phase cell forces the G2 nucleus to condense prematurely.