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Fig. 1. Polo kinase and stabilized Cyclin A modify the PIMdba phenotype.
(A-F) DNA staining at stage 14 reveals the presence of many large polyploid
abnormal nuclei in the CNS of embryos expressing the stabilized securin
PIMdba if they are also polo mutant (E,F;
pimdba polo-). By contrast, at this stage,
cells in the CNS are hardly affected in polo mutants that do not
express PIMdba (C,D; polo-) or in the
polo+ siblings that express PIMdba (A,B;
pimdba). B, D and F show high-magnification views with the
CNS from the embryos displayed in A, C and E, respectively. (G-J) Using
prd-GAL4 and UAS-CycA
1-53, stabilized Cyclin
A was expressed in alternating embryonic segments. Expressing segments are
indicated by arrowheads in G and I or by white lines in H and J, which display
high-magnification views of epidermal regions. DNA staining indicates that the
metaphase delay caused by stabilized Cyclin A is prolonged in embryos that
also express the stabilized securin PIMdba under the control of the
pim+ regulatory region. Compared with embryos without
PIMdba (G,H; CycA
N), metaphase plates
(arrows) in regions with stabilized Cyclin A are enriched in embryos that also
express PIMdba (I,J; pimdba
CycA
N).