A NEW-TYPE OF REPEATED ELEMENTS IN THE RDNA INTERGENE SPACER OF DIPLOID AEGILOPS UMBELLULATA

Three regions of the rDNA intergene spacer of Aegilops umbellulata wer e sequenced. It was found that the rDNA intergene spacer of Ae, umbell ulata, like that of Triticum aestivum, includes four main types of rep eated elements. The transcribed region of the Ae. umbellulata spacer d iffers from those of the related species of the Triticeae tribe in tha t it has a 132-bp insert composed of five copies of a 26-bp element th at includes an inverted repeat and is homologous to the conservative p art of the assumed promoter region. It is suggested that this repeated element may serve as a transcription enhancer.