(SA1 phenocluster). The telophase-like figures of msps RNAi cells display abnormally long astral microtubules. Scale bar, 5 mm. Found at: doi:10.1371/journal.pgen.1000126.s011 (3.48 MB TIF) Figure S12 Extremely short spindles and monopolar spindles observed after RNAi for eIF-3p66 (translation factor) and CG4865. Anaphases are very rare, suggesting that the tiny spindles in these cells are unable to support chromosome segregation. Scale bar, 5 mm. Found at: doi:10.1371/journal.pgen.1000126.s012 (2.75 MB TIF) Figure S13 Disorganized spindles with low microtubule density observed after RNAi for genes of the SA2 phenocluster. The elongated ana/telophase-like spindles contain scattered chromo- somes with unseparated sister chromatids. Scale bar, 5 mm. Found at: doi:10.1371/journal.pgen.1000126.s013 (2.06 MB TIF) Figure S14 Anastral and broad spindle poles observed after RNAi for abnormal spindle (asp). Scale bar, 5 mm. Found at: doi:10.1371/journal.pgen.1000126.s014 (1.45 MB TIF) Figure S15 RNAi phenotypes observed in the heterogeneous SA4 group. In most cdc2 RNAi cells, the chromosomes remain at the center of the cells (as seen after RNAi for the CS4 group genes) and the centrosomes detach from the spindle poles. In Klp61F RNAi cells, spindles are either monopolar or monastral bipolar. In cells with monastral bipolar spindles, chromosome segregation does not occur and the chromosomes remain associated with the astral poles. Scale bar, 5 mm. Found at: doi:10.1371/journal.pgen.1000126.s015 (3.93 MB TIF) Figure S16 Abnormal chromosome condensation and multiple mitotic defects observed after RNAi for Borr (SC1) and Myb (SC2). Ctr, control; c-meta, colchicine/hypotonic-treated metaphase chromosomes. Note that in Borr RNAi cells chromosomes are abnormally long and irregularly condensed. 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PLoS Genetics | www.plosgenetics.org 17 July 2008 | Volume 4 | Issue 7 | e1000126