title: On the origin of the eukaryotic chromosome: the role of noncanonical DNA structures in telomere evolution.
abstract: The transition of an ancestral circular genome to multiple linear chromosomes was crucial for eukaryogenesis because it allowed rapid adaptive evolution through aneuploidy. Here, we propose that the ends of nascent linear chromosomes should have had a dual function in chromosome end protection (capping) and chromosome segregation to give rise to the "proto-telomeres." Later on, proper centromeres evolved at subtelomeric regions. We also propose that both noncanonical structures based on guanine-guanine interactions and the end-protection proteins recruited by the emergent telomeric heterochromatin have been required for telomere maintenance through evolution. We further suggest that the origin of Drosophila telomeres may be reminiscent of how the first telomeres arose.
authors.affiliation: Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049 Madrid, Spain.
authors.forename: Miguel
authors.initials: M
authors.lastname: Garavís
authors.forename: Carlos
authors.initials: C
authors.lastname: González
authors.forename: Alfredo
authors.initials: A
authors.lastname: Villasante
mesh_terms: D000818:Animals; D002503:Centromere / Q000235:genetics; D002875:Chromosomes / Q000235:genetics*; D019143:Evolution, Molecular; D054856:G-Quadruplexes; D006801:Humans; D018626:Retroelements; D019098:Telomerase / Q000378:metabolism; D016615:Telomere / Q000235:genetics* / Q000378:metabolism
chemical_list: D018626:Retroelements; D019098:Telomerase
keywords: G-quadruplexes; centromeres; non-LTR retrotransposons; telomeres