Fig. 3. FISH to an episomal plasmid maintained in one nucleus shows nuclei are inherited with mirror image symmetry and that the nuclei never mix. (A) Interphase; the FISH probe hybridizes to the episome contained in the right nucleus. (B) In the metaphase nuclei, stacked on top of each other in the cell center, FISH signal is detected in the dorsal nucleus. (B') Projection of the first eight z-sections, dorsal nucleus, of the cell seen in B contains the FISH signal. (B") Projection of the last eight z-sections, ventral nucleus, of the cell shown in B shows the FISH signal is excluded. (C) During cytokinesis, one nucleus in each daughter is labeled with mirror image symmetry between the two cells. Red, DAPI; green, FISH. Bars, 2 µm.