Telomere replication, kinetochore organizers, and satellite DNA evolution

摘要: Robertsonian rearrangements demonstrate one-break chromosome rearrangement and the reversible appearance disappearance of telomeres centromeres. Such events are quite discordant with classical cytogenetic theories, which assume all to require at least two breaks consider centromeres as immutable structures rather than determined by mutable DNA sequences. Cytogenetic data from spontaneous induced telomere-telomere fusions in mammals support a molecular model terminal synthesis similar recombine before replication subsequent separation. This, along evidence for hypothetical sequence, kinetochore organizer, readily explains latent telomeres, centromeres, (one-break) rearrangements. A second model, involving simply recombination between like satellite sequences on different chromosomes, not only how one can simultaneously evolve but also why is usually located near or it maintains preferred orientation respect centromere.