paliulis and nicklas curr. biol. chromatid individualization as cells enter mitosis involves...

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Paliulis and Nicklas Curr. Biol.

Chromatid individualization as cells enter mitosis involves dissociation of most cohesin (red symbols) from chromosomes, which is regulated by PLK. This processcoincides with condensin’s (green symbols) association with chromosomes and their compaction. Cohesin remaining on chromosomes, largely at centromeres, is then cleaved by separase at the metaphase-to-anaphase transition.

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blobs

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Insert length of DNA into channels, channels “entropically stretch.”

Fig. 7. Transient replication factory model with initiation at the cell center. We forced the replisomes to stay in the cell center region (»1/6 of the total nucleoid length in the center) until 50% of the chain has been replicated (see the replisome trajectories on the right). Note that a symmetric, bimodal distribution appears very early in the replication stage. The left–right segregation symmetry is due to the organization the circular chain (90° rotated such that ori–ter are located at the cell center instead of cell poles). The parameters are (Dshell = 0.75s for Rout = 5.5s and Rin = 4.75s).

Fig. 8. The effect of shell thickness of the concentric shell on the segregation dynamics. Same simulation as the one in Fig. 5 in the presence of factory; the only difference is the shell thickness Dshell = 0.75s for Rout = 5.5s and Rin = 4.75s (whereas Dshell = 1.25s for Rout = 5.5s and Rin = 4.25s). Note that as the shell becomes thinner than the size of the beads (thus smaller than the width of the chain), the diffusion also becomes slower, thus, resulting in the delay of ori–ter crossing. Also on the right, we show the replisome trajectories.