Structure of the Astasia longa rDNA promoter and the 5 ' region of the 19SrRNA gene

We sequenced the promoter and the 5' region of the 19S rRNA gene of Astasia longa (Flagellata) and mapped the 5' end of the gene with reverse transcri ptase. The gene proved highly homologous to its Euglena gracilis var bacill aris counterpart, suggesting close phylogenetic relations of these species. Sequences conserved among Flagellata and Saccharomyces cerevisiae were fou nd in the 5'-region of the gene. The promoter region upstream of the A. lon ga 19S rRNA gene was shown to contain a repetitive sequence which is charac teristic of gene promoters of Giardia lamblia (Flagellata) and is possibly involved in transcription regulation.