sentence: In agreement with our results , cell expansion and post-mitotic stabilization of CYCA1 ; 1 , CYCB1 ; 1 and CYCB2 ; 1 ( Mews et al. 1997 , 2000 ) and endoreduplication ( Ogawa et al. 2010 ) all occur in the elongation zone of the maize root , further suggesting a link between reduced proteolysis of certain cyclins , cell expansion and endoreduplication .