ibclogo XVI International Botanical Congess

Abstract Number: 6197
Poster No. = 2588


rDNA OF SOLANACEAE: SUBREPEAT REARRANGEMENT IN ALLOPLOIDS


R.A.Volkov1, I. I. Panchuk2, V. Hemleben2, 1University of Chernivtsy, 274012, Ukraine, 2University of Tübingen, 72076, Germany


Intergenic spacer region (IGS) in 18-25S rDNA of natural allotetraploid Nicotiana tabacum has a structure which differ from that one of the presumptive diploid progenitors (N. sylvestris and N. tomentosiformis). In order to explain this phenomenon we have cloned and sequenced IGS regions from N. tabacum, N. sylvestris and N. tomentosiformis and shown that N. tabacum rDNA originate from paternal N. tomentosiformis whereas rDNA of maternal N. sylvestris is eliminated. rDNA transcription silencing/differential elimination by nucleolar dominance in N. tabacum is connected with subrepeat amplification upstream and downstream of TIS suggesting its enhancers function. IGS reconstruction has been also observed in artificial interspecific hybrids of Solanum.

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