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On the origin of telomeres: a glimpse at the pre‐telomerase world
Author(s) -
Nosek Jozef,
Kosa Peter,
Tomaska Lubomir
Publication year - 2006
Publication title -
bioessays
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.175
H-Index - 184
eISSN - 1521-1878
pISSN - 0265-9247
DOI - 10.1002/bies.20355
Subject(s) - telomere , eukaryotic chromosome fine structure , genome , biology , telomerase , circular bacterial chromosome , genetics , dna , evolutionary biology , gene
Chromosomes may be either circular or linear, the latter being prone to erosion caused by incomplete replication, degradation and inappropriate repair. Despite these problems, the linear form of DNA is frequently found in viruses, bacteria, eukaryotic nuclei and organelles. The high incidence of linear chromosomes and/or genomes evokes why and how they emerged in evolution. Here we suggest that the primordial terminal structures (telomeres) of linear chromosomes in eukaryotic nuclei were derived from selfish element(s), which caused the linearization of ancestral circular genome. The telomeres were then essential in solving the emerged problems. Molecular fossils of such elements were recently identified in phylogenetically distant genomes and were shown to generate terminal arrays of tandem repeats. These arrays might mediate the formation of higher order structures at chromosomal termini that stabilize the linear chromosomal form by fulfilling essential telomeric functions. BioEssays 28: 182–190, 2006. © 2006 Wiley periodicals, Inc.