sentence: Since D - , A - and B-type cyclins characteristically control progression through distinct phases of the cell cycle , we investigated whether the amount of kinase activity associated with CYCA1 , CYCB1 ;3 , CYCD2 ; 1 and CYCD5 differed in endosperm at 7 DAP ( mitotic stage ) , 11 DAP ( mitotic to endoreduplication transition stage ) , and 15 DAP ( endoreduplication stage ) .