Analysis of chromosome termini in potato varieties

Abstract

Chromosomes of potato (Solanum tuberosum) are terminated by telomeres, which are formed by tandemly repeated [TTTAGGG]n oligonucleotide sequence. The total length of blocks of telomeric DNA has been known to vary largely among plant species and their varieties, and also among individual chromosome arms within a single nucleus. To check for such differences in potato varieties, which could be of a possible use in genotyping, we performed pulsed-field gel electrophoretic analysis of terminal restriction fragments in selected potato varieties. We found a typical range of telomere lengths of 20-60 kb in most analysed varieties. In one of analysed varieties (Monalisa), telomeres of wider span (up to 80 kb) have been observed. Most of restriction enzymes (PvuII, HaeIII, TaqI) produced a resulting smeared hybridisation pattern of telomeres. When using BglII, however, a doublet hybridisation band could be observed. This may reflect differences in composition of telomere-associated sequences at different chromosome ends.