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Expectations fulfilled. I find it quite interesting philosophically that two different groups approached the cell cycle with different expectations and each found exactly what they were looking for. At first, the results looked very different, perhaps because we were imposing our expectations. I approached the study of the cell cycle with the paradigm of bacteriophage morphogenesis in mind. Indeed what we found looked a lot like phage morphogenesis a series of gene controlled, dependent events leading to progressive stages in division. Paul Nurse, on the other hand, was most interested in rate limiting steps. He found a rate-limiting step at mitosis controlled by the cdc2 gene of S. pombe From this point of view, the most important gene of fission yeast, cdc2, seemed very different than what we viewed as the most important gene in budding yeast, CDC28, because the former acted in G2 while the latter acted in G1. Once it became clear that the two genes could substitute for one another, the apparent differences were resolved. In fact, both proteins acted in each organism at G1 and G2. Under rapid growth conditions the G1 activation of CDC28 in S. cerevisiae is dependent on cell growth while in S. pombe it is the G2 activation of cdc2 that is dependent on growth.