engleski

The nucleotide sequence and structural features of rDNA spacer region between 25S and 18S rRNA genes in Quercus petraea

Intergenic spacer region (IGS) between 25S and 18S rRNA genes is evolutionary more unstable than rRNA coding regions in eukaryotic DNA, though it contains several structural elements involved in control and regulation of rRNA transcription. One of these elements are enhancers, of which copy number varies usually between the spacers of different rDNA clusters in the same genome, creating the spacer length variants (slvs). Copy number of enhancer elements and transcriptional activity of individual rRNA genes in an rRNA cluster are positively correlated. In Q. petrea there are at least 5 different slvs of around 560, 1200, 1400, 2000 and 3500 pb in length. After determination of complete nucleotide sequence of dominant slvs in the genome, detailed structured analysis was performed in order to reveal: (i) the position of gene promoter and spacer promoters, (ii) the main repeat element containing enhancer elements.

ribosomal genes; IGS; spacer length variants

nije evidentirano