The Cell Cycle Timing of Centromeric Chromatin Assembly in Drosophila Meiosis Is Distinct from Mitosis Yet Requires CAL1 and CENP-C
(A) Testes from pre-pupal larvae propagated at 29°C were fixed and stained with anti-CID (red) and anti-CENP-C (green) antibodies, and DAPI (grey). Wild type control, bam-Gal4-VP-16; CID-RNAi, bam-Gal4-VP-16/+; UAS-Cid-RNAi; CAL1 RNAi, bam-Gal4-VP16/+; UAS-Cal1-RNAi; CENP-C RNAi, bam-Gal4-VP16/+; UAS-Cenp-C-RNAi. Nuclei in meiotic prophase I, stages S1 and S6, are shown. White arrows indicate CENP-C localization in the nucleolus. Scale bar: 10 µM. (B) Quantitation of total centromeric CID fluorescent intensity per nucleus in wild-type, CID-, CAL1-, and CENP-C-RNAi in stages S1 and S6. For each graph, the S6 is normalized to the S1 value. N = control S1; 54, S6; 27, CID-RNAi S1; 92, S6; 52, CAL1-RNAi S1; 112, S6; 5, CENP-C-RNAi S1; 110, S6; 46. (C) Testes from pre-pupal larvae propagated at 29°C were fixed and stained with anti-CID (red) and anti-tubulin (green) antibodies and DAPI (grey). Representative images for chromosome segregation in meiosis I and II in control, CID-, CAL1-, and CENP-C-RNAi are shown. Scale bar: 10 µM. (D) Quantitation of the percentage of chromosome mis-segregation events in control, CID-, CAL1-, or CENP-C RNAi, in 32 cell cysts (M6 stage) after meiosis I and 64 cell cysts (T1–T3 stages) after meiosis II.