Mutant Phenotype
Wee1 acts as a dosage-dependent inhibitor of mitosis. Thus, the amount of Wee1 protein correlates with the size of the cells:
The fission yeast mutant wee1, also called wee1-, divides at a significantly smaller cell size than wildtype cells. Since Wee1 inhibits entry into mitosis, its absence will lead to division at a premature stage and sub-normal cell size. Conversely, when Wee1 expression is increased, mitosis is delayed and cells grow to a large size before dividing.
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