The genome size estimation and telomeric-repeat motifs of thirteen Arctic plants

As a preliminary step of genome analysis, we produced a total of 28–44 Gb DNA sequencing data of whole-genome for thirteen Svalbard plants. We estimated genome sizes using these data with a k-mer-based computation tool and found that genome sizes of eight species ranged from 180–894 Mb: Cochlearia groenlandica 180 Mb, Dryas octopetala 204 Mb, Eriophorum scheuchzeri ssp. arcticum 306 Mb, Oxyria digyna 352 Mb, Salix polaris 383 Mb, Betula nana 689 Mb, Cassiope tetragona 798 Mb, and Silene uralensis ssp. arctica 894 Mb. We could not estimate the genome size of the other five species. We also analyzed variations in DNA sequences by identifying putative telomeric-repeat motifs in the thirteen Svalbard plants. Eleven out of thirteen species contained the canonical plant telomeric-repeat motif, TTTAGGG ( Arabidopsis -type), whereas S. oppositifolia contained the Chlamydomonas -type telomeric-repeat motif (TTTTAGGG) and P. dahlianum had a novel telomeric-repeat motif, TTCAGGG. These findings provide a quantitative guideline for whole-genome sequencing analysis of Arctic plants in the future. The findings in this study provide a quantitative guideline for whole-genome sequencing analysis of Arctic plants, and they also show the potential of Arctic plants to be a new source of telomere diversity.