The centromeric regions of potato chromosomes contain megabase-sized tandem arrays of telomere-similar sequence

Chromosoma. 2004 Sep;113(2):77-83. doi: 10.1007/s00412-004-0297-1. Epub 2004 Jul 16.

Abstract

Telomere-similar sequences have been found in non-telomeric regions in various eukaryotic species. Centromeric regions often harbor such interstitial telomeric repeats (ITRs). We isolated a 2.8 kb ITR, pSbTC1, in a diploid potato species Solanum bulbocastanum. DNA sequences related to the pSbTC1 family are widely distributed in different Solanum species. The pSbTC1-related sequences are organized into tandem arrays and located mainly in the centromeric regions of potato chromosomes. Most notably, the pSbTC1-related sequences have undergone extensive amplification and a single array can span up to multiple megabases. These results suggest that the pSbTC1-related sequences are not simple relics of ancient events in karyotype evolution, such as chromosomal fusions. We also demonstrated that the pSbTC1-related sequences are heavily methylated and are associated with highly condensed centromeric heterochromatin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Centromere / genetics*
  • DNA Methylation
  • DNA, Plant / genetics*
  • Heterochromatin / genetics*
  • Molecular Sequence Data
  • Sequence Homology, Nucleic Acid
  • Solanum / genetics*
  • Telomere / genetics*

Substances

  • DNA, Plant
  • Heterochromatin