If the cap fits, wear it: an overview of telomeric structures over evolution

Cell Mol Life Sci. 2014 Mar;71(5):847-65. doi: 10.1007/s00018-013-1469-z. Epub 2013 Sep 17.


Genome organization into linear chromosomes likely represents an important evolutionary innovation that has permitted the development of the sexual life cycle; this process has consequently advanced nuclear expansion and increased complexity of eukaryotic genomes. Chromosome linearity, however, poses a major challenge to the internal cellular machinery. The need to efficiently recognize and repair DNA double-strand breaks that occur as a consequence of DNA damage presents a constant threat to native chromosome ends known as telomeres. In this review, we present a comparative survey of various solutions to the end protection problem, maintaining an emphasis on DNA structure. This begins with telomeric structures derived from a subset of prokaryotes, mitochondria, and viruses, and will progress into the typical telomere structure exhibited by higher organisms containing TTAGG-like tandem sequences. We next examine non-canonical telomeres from Drosophila melanogaster, which comprise arrays of retrotransposons. Finally, we discuss telomeric structures in evolution and possible switches between canonical and non-canonical solutions to chromosome end protection.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Chromosomes / genetics*
  • DNA / chemistry*
  • Evolution, Molecular*
  • Models, Molecular*
  • Nuclear Proteins / metabolism
  • Nucleic Acid Conformation*
  • Telomerase / metabolism*
  • Telomere / genetics*
  • Telomere Homeostasis / physiology*


  • Nuclear Proteins
  • terminin
  • DNA
  • Telomerase