Figure 5.
Is the yeast spindle comparable to one mammalian kinetochore? (a) The segregation apparatus in budding yeast is composed of kinetochore and interpolar microtubules ( green) and pericentric chromatin organized into C-loops of intramolecularly paired chromatids (136). Sister centromeres are separated by an average of 800 nm in mitosis (97), and are clustered into a single diffraction-limited spot in mitosis. (b) Longitudinal section through a HeLa cell in prometaphase (109a). The trilaminar structure of a mammalian kinetochore is marked by the orange and red dots. Multiple attachment sites may be clustered whether they are on separate chromosomes (as in budding yeast) or within a single chromosome (as in the Hela cell shown here).