AIR-2/Aurora B anaphase behavior is altered in the presence of univalents. (A) Wild-type anaphase spindles stained for DNA (blue), tubulin (green), SEP-1, and AIR-2 (red in merge). The chromosome segregation distances and spindle morphology were used to determine the anaphase stages. Diagrams depict DNA (blue), microtubules (green), AIR-2 (yellow), the rings without AIR-2 (red), and the rings containing AIR-2 (orange). (B) AIR-2 behavior in spindles containing univalents in either the him-8(me4) or the zim-1(tm1813) mutant. In some spindles, AIR-2 relocalizes to microtubules by mid anaphase (row 1), whereas in others, AIR-2 remains ring associated in MI (row 2) and MII (rows 3 and 4); note that in MII, AIR-2 also displays polar body localization. AIR-2 always relocalizes by late anaphase (row 5). (C) Quantification of mid anaphase spindles with AIR-2 in rings for control, him-8(me4), and zim-1(tm1813) MI and MII spindles. Bars, 2.5 µm.