Nucleotide sequence of the internal transcribed spacers of ribosomal DNA in Picea abies Karst

Abstract

The nucleotide sequences of the internal transcribed spacers (ITS1 and ITS2) of ribosomal DNA from Picea abies are reported. Two types of ITS1 of 2784 bp and 3271 bp long exist, whereas only one ITS2 type 238 bp long is present in this species. The shorter ITS1 is characterized by three shorter subrepeats: ssr1, ssr2 and ssr3, 221 bp, 227 bp and 226 bp long respectively. Between the ssr1 and ssr2 sub-repeats are inserted three longer sub-repeats: LSR1, LSR2 and LSR3, 480 bp, 480 bp and 581 bp long respectively. The similarity between the three ssr range from 66% to 79% and between the three LSR range from 65% to 96%. At the end of the LSR3 a microsatellite of 14 CT elements is present. The longer ITS1 type is due to a duplication of the LSR1, most probably obtained by unequal crossing-over and it has an identity of 97.3% with the shorter ITS1 type.