Chromosome Research

, Volume 10, Issue 2, pp 155–164

Aloe spp. – plants with vertebrate-like telomeric sequences

  • Hanna Weiss
  • Harry Scherthan

DOI: 10.1023/A:1014905319557

Cite this article as:
Weiss, H. & Scherthan, H. Chromosome Res (2002) 10: 155. doi:10.1023/A:1014905319557


Chromosome termini of most eukaryotes end in tracks of short tandemly repeated GC-rich sequences, the composition of which varies among different groups of organisms. Plant species predominantly contain (TTTAGGG)n repeats at their telomeres. However, a few plant species, including members of Alliaceae and Aloe spp. (Asphodelaceae) were found to lack such Arabidopsis-type (T3AG3)n telomeric repeats. Recently, it has been proposed that the lack of T3AG3 telomeric repeat sequences extends to all species forming the Asparagales clade. Here, we analysed the composition of Aloe telomeres by single-primer PCR and fluorescence in-situ hybridization (FISH) with directly labelled Arabidopsis-type (TTTAGGG)28–43 DNA probe, and with vertebrate-type (TTAGGG)33–50 DNA and a (C3TA2)3 peptide nucleic acid (PNA) probe. It was found that Nicotiana tabacum contained Arabidopsis-type telomeric repeats, while Aloe telomeres lacked the corresponding FISH signals. Surprisingly, FISH with the highly specific vertebrate-type (C3TA2)3 PNA probe resulted in strong T2AG3-specific FISH signals at the ends of chromosomes of both Aloe and Nicotiana tabacum, suggesting the presence of T2AG3 telomeric repeats in these species. FISH with a long (TTAGGG)33–50 DNA probe also highlighted Aloe chromosome ends, while this probe failed to reveal FISH signals on tobacco chromosomes. These results indicate the presence of vertebrate-like telomeric sequences at the telomeres of Aloe spp. chromosomes. However, single-primer PCR with (T2AG3)5 primers failed to amplify such sequences in Aloe, which could indicate a low copy number of T2AG3 repeats at the chromosome ends and/or their co-orientation and interspersion with other repeat types. Our results suggest that telomeres of plant species, which were thought to lack GC-rich repeats, may in fact contain variant repeat types.

Aloe Asparagales evolution fluorescence in-situ hybridization PCR PNA telomere TTAGGG 

Copyright information

© Kluwer Academic Publishers 2002

Authors and Affiliations

  • Hanna Weiss
    • 1
  • Harry Scherthan
    • 2
  1. 1.Department of Higher Plant Systematics & Evolution, Institute of BotanyUniversity of Vienna, Rennweg 14WienAustria
  2. 2.Department of Human Biology & Human GeneticsUniversity of Kaiserslautern, Erwin-Schrödingerstr.KaiserslauternGermany
  3. 3.Max-Planck-Inst. for Molecular Genetics, Ihnestr. 73BerlinGermany

Personalised recommendations