genetic application cell cycle process

Question 1

The M-phase Promoting Factor (MPF)

Answer 1

• key factor promoting the maturation of frog oocytes in Xenopus. The exogenous application of MPF to cells in any phase of the cell-cycle was sufficient to induce mitosis.
  -Consist of two subunit: cdc/cdk and cyclin

Question 2

Present of cdc and cyclin

Answer 2

• the level of cdc/cdk remain Constance in the cell while cyclin show fluctuation
  -the dimer can be target by Ubiquitinese which add ubiquitine to cyclin, causing breakdown by 26s protosome

Question 3

Using conditional mutant to study cell cycle

Answer 3

viable mutants that could be maintained and grow under permissive conditions (low temperature) but could also be observed for their mutant phenotype under restrictive conditions

Question 4

Two class of mutant identify by conditional

Answer 4

wee (“small”) mutants- constitutive and temperature sensitive mutants. Display reduced cell size, which is exacerbated at the restrictive temperature for temperature sensitive mutants
cdc (cell division cycle) mutants – all are temperature sensitive with a block in cell division at the restrictive
temperature (35°C). Some also show elongated cell morphology at the permissive temperature.

Question 5

location of cdc and wee1 mutant

Answer 5

Crosses were performed between mutants to test for allelism using using complementation and/or segregation analysis
-both of them have independent opposing role upstream of cdc2