Loss of centromeric pairing and cohesion in AtCTF7 -RNAi male meiocytes. FISH of male meiotic chromosome spreads hybridized with a centromeric probe showing DAPI (blue) and probe (red). (A-L) Untreated transgenic AtCTF7-RNAi line, (M-X) transgenic AtCTF7-RNAi line treated with dexamethasone. For each panel, left column shows merged images of DAPI and the probe, the middle column shows DAPI, and the right column shows the probe alone. (A-C) Early leptotene cell showing 10 centromeres. (D-F) Late zygotene showing 5 centromeric signals as a result of synapsis of centromeres. (G-I) Pachytene showing 5 centromeric signals as synapsis of chromosomes is complete. (J-L) Diplotene. (M-O, P-R) Early meiotic prophase, showing more than 10 centromeric signals. (S-U, V-X) Mid meiotic prophase stages, showing more than 10 centromeric signals (S-U) and 6 centromeric signals (V-X).