Phylogenetic divergence in Asparagales plants is associated with switches in telomere sequences. The last switch occurred with divergence of the genus Allium (Amaryllidaceae) from the other Allioideae (formerly Alliaceae) genera, resulting in uncharacterized telomeres maintained by an unknown mechanism. To characterize the unknown Allium telomeres, we applied a combination of bioinformatic processing of transcriptomic and genomic data with standard approaches in telomere biology such as BAL31 sensitivity tests, terminal restriction fragment analysis, the telomere repeat amplification protocol (TRAP), and fluorescence in situ hybridization (FISH). Using these methods, we characterize the unusual telomeric sequence (CTCGGTTATGGG)n present in Allium species, demonstrate its synthesis by telomerase, and characterize the telomerase reverse transcriptase (TERT) subunit of Allium cepa. Our findings open up the possibility of studying the molecular details of the evolutionary genetic change in Allium telomeres and its possible role in speciation. Experimental studies addressing the implications of this change in terms of the interplay of telomere components may now be designed to shed more light on telomere functions and evolution in general.

Institute of Biophysics Czech Academy of Sciences Královopolská 135 CZ 61265 Brno Czech Republic

Laboratory of Functional Genomics and Proteomics National Centre for Biomolecular Research Faculty of Science Masaryk University Kamenice 5 CZ 62500 Brno Czech Republic

Mendel Centre for Plant Genomics and Proteomics Central European Institute of Technology Masaryk University Kamenice 5 CZ 62500 Brno Czech Republic

References provided by Crossref.org

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AY818171.1, DRX005522, KM117264, KM117265, KT381713, SRX188612