Fig. 2. A speculative working model showing the dependency pathways for association of components with the animal kinetochore. This interpretation of data presented previously (Fukagawa and Brown, 1997; Howman et al., 2000; Fukagawa et al., 2001; Oegema et al., 2001; Desai et al., 2003; Liu et al., 2003; Goshima et al., 2003; Cheeseman et al., 2004) should not be interpreted as showing direct physical interactions. Components shown in blue have thus far been identified only in C. elegans. Those shown in dotted boxes have been shown to form complexes.