[PROVISIONAL] Does the chromosomal position of 35S rDNA sites influence their transcription? A survey on Nothoscordum species (Amaryllidaceae)

Abstract 35S ribosomal DNA (rDNA) sites are the regions where the ribosomal genes 18S, 5.8S and 25S, responsible for the formation of the nucleoli, are found. The fact that rDNA sites have non-random distribution on chromosomes suggests that their position on the chromosome may influence their transcription. In order to identify if the preferentially transcribed rDNA sites occupy a specific position, six species (nine cytotypes) of Nothoscordum genus were analyzed using two different techniques to impregnate the nucleolar organizer regions (NORs) with silver nitrate. Both techniques strongly s...