caa a22 4500 477039413 CHVBK 20180405111313.0 cr unu---uuuuu 170330e19960301xx s 000 0 eng 10.1007/BF00989055 doi (NATIONALLICENCE)springer-10.1007/BF00989055 Molecular organization and evolution of the external transcribed rDNA spacer region in two diploid relatives of Nicotiana tabacum ( Solanaceae ) [Elektronische Daten] [R. Volkov, S. Kostishin, F. Ehrendorfer, D. Schweizer] For two close diploid relatives of the allotetraploidNicotiana tabacum, N. sylvestris (subg.Petunioides) andN. tomentosiformis (subg.Nicotiana), the nucleotide sequences of the external transcribed rDNA spacer regions (ETS) are described and compared (within the genus and with otherSolanaceae). The ETS of these two diploid species consists of three regions: the most upstream region I contains the putative RNA polymerase I transcription initiation site. Region II consists of several subrepeats (type A) and of a short species specific element. There are 5 subrepeats in theN. sylvestris clone and 10 subrepeats in the clone isolated fromN. tomentosiformis. Region III, adjacent to the 18S rRNA gene, exhibits much higher similarities between species than regions I and II, not only amongN. sylvestris andN. tomentosiformis but also with more distantly relatedSolanaceae. At the 5′-end of region III of the ETS in the twoNicotiana species studied in detail there are three copies of highly divergent subrepeats (type B). Possible ways of the step-wise molecular evolution of these ribosomal DNA regions inNicotiana and theSolanaceae are discussed. Springer-Verlag, 1996 Solanaceae nationallicence Nicotiana nationallicence rDNA nationallicence external transcribed spacer nationallicence phylogenetic subrepeat differentiation nationallicence molecular evolution nationallicence Volkov R. Department of Biochemistry, State University of Chernivtsy, Kotsubinsky str. 2, 274012, Chernivtsy, Ukraine aut Kostishin S. Department of Biochemistry, State University of Chernivtsy, Kotsubinsky str. 2, 274012, Chernivtsy, Ukraine aut Ehrendorfer F. Institute of Botany of the University of Vienna, Rennweg 14, A-1030, Vienna, Austria aut Schweizer D. Institute of Botany of the University of Vienna, Rennweg 14, A-1030, Vienna, Austria aut Plant Systematics and Evolution Springer-Verlag 201/1-4(1996-03-01), 117-129 0378-2697 201:1-4<117 1996 201 606 https://doi.org/10.1007/BF00989055 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00989055 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Volkov R. Department of Biochemistry, State University of Chernivtsy, Kotsubinsky str. 2, 274012, Chernivtsy, Ukraine aut NATIONALLICENCE 700 1- Kostishin S. Department of Biochemistry, State University of Chernivtsy, Kotsubinsky str. 2, 274012, Chernivtsy, Ukraine aut NATIONALLICENCE 700 1- Ehrendorfer F. Institute of Botany of the University of Vienna, Rennweg 14, A-1030, Vienna, Austria aut NATIONALLICENCE 700 1- Schweizer D. Institute of Botany of the University of Vienna, Rennweg 14, A-1030, Vienna, Austria aut NATIONALLICENCE 773 0- Plant Systematics and Evolution Springer-Verlag 201/1-4(1996-03-01), 117-129 0378-2697 201:1-4<117 1996 201 606 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer