Figure 8.

Summary model of the transition from the mitotic to the endoreduplicative cell cycle. This depicts the current interpretation of the analysis of expression of the cyclins A, B, and E and regulation of their associated kinase activities in relation to the cell cycle events involved with the shift from proliferation to endoreduplication. The solid lines indicate the accumulation of the respective cyclin protein. For cyclins A and E, the associated kinase activity is assumed to follow the protein expression fairly closely. The dashed line indicates the cyclin B-associated kinase activity, because it is suppressed during the first endocycle despite the continued expression of the protein.