Model for RPM contribution to pairing.

Two pairs of homologs are diagrammed but only one chromatid is shown for each chromosome. Centromeres remain in close proximity following dissolution of the Rabl orientation (the first change diagrammed) due to a centromere-specific mechanism that joins pairs of nonhomologous centromeres but telomere anchoring to the nuclear envelope can hold chromosome arms apart. Short chromosomes depend more than long chromosomes on long range telomere movements that allow and generate collisions that in turn promote homology assessment, stabilization of association and synapsis.