Fig 1.
In monocentric chromosomes, kinetochore (red circles) can be easily identified as it is located at the chromosomal primary constriction (centromere) during metaphase (M, top box). At anaphase (A, top box) chromatids move towards poles after their attachment to microtubules and V-shaped structures can be observed resulting from the passive movement of the chromosomal arms. In holocentric chromosome a chromosome-wide kinetochore is present (red lines) and no primary constriction is present during metaphase (M, bottom box). During anaphase (A, top box) holocentric chromatids move towards poles as linear bars parallel. If a chromosomal breakage occurs in a monocentric chromosome (bottom box), acentric chromosome fragments cannot be attached to microtubules during metaphase (M) and they are lost during anaphase (A). On the contrary, chromosome breakage of a holocentric chromosome results in chromosomal fragments that retain kinetic activity due to the chromosome-wide centromere extension and can be properly inherited.
Fig 2.
Schematic comparison of the chromosomal separation occurring during the first meiotic division in standard and inverted meiosis.