Stage 1: Initial contacts (‘coupling’): Many organisms use centromeres (budding yeast) or telomeres (mouse) as the initial point of contact (see text). The contacts can occur either between homologs or between non-homologs.
Stage 2: Tethering of chromosomes to the nuclear envelope: Using the conserved SUN-KASH proteins (see blow up section on right), telomeres (as in fission yeast) centromeres (as in Drosophila oocytes) or other specialized regions (as in C. elegans) are tethered to the nuclear envelope.
Stage 3: Nuclear movements: Dramatic movements specific to meiotic prophase promote homolog alignment and ‘shake off’ unwanted interactions with non-homologous sequences.