Silenced rRNA genes are activated and substitute for partially eliminated active homeologs in the recently formed allotetraploid, Tragopogon mirus (Asteraceae)

0446339 - BFÚ 2016 RIV GB eng J - Článek v odborném periodiku
Dobešová, Eva - Malinská, Hana - Matyášek, Roman - Leitch, A. R. - Soltis, D. E. - Kovařík, Aleš
Silenced rRNA genes are activated and substitute for partially eliminated active homeologs in the recently formed allotetraploid, Tragopogon mirus (Asteraceae).
Heredity. Roč. 114, č. 3 (2015), s. 356-365. ISSN 0018-067X. E-ISSN 1365-2540
Grant CEP: GA ČR(CZ) GA14-34632S; GA ČR(CZ) GA13-10057S
Institucionální podpora: RVO:68081707
Klíčová slova: NUCLEOLAR DOMINANCE * POLYPLOID PLANTS * POLYPLOID PLANTS
Kód oboru RIV: BO - Biofyzika
Impakt faktor: 3.801, rok: 2015

To study the relationship between uniparental rDNA (encoding 18S, 5.8S and 26S ribosomal RNA) silencing (nucleolar dominance) and rRNA gene dosage, we studied a recently emerged (within the last 80 years) allotetraploid Tragopogon mirus (2n= 24), formed from the diploid progenitors T. dubius (2n= 12, D-genome donor) and T. porrifolius (2n= 12, P-genome donor). Here, we used molecular, cytogenetic and genomic approaches to analyse rRNA gene activity in two sibling T. mirus plants (33A and 33B) with widely different rRNA gene dosages. Plant 33B had similar to 400 rRNA genes at the D-genome locus, which is typical for T. mirus, accounting for similar to 25% of total rDNA. We observed characteristic expression dominance of T. dubius-origin genes in all organs. Its sister plant 33A harboured a homozygous macrodeletion that reduced the number of T. dubius-origin genes to about 70 copies (similar to 4% of total rDNA). It showed biparental rDNA expression in root, flower and callus, but not in leaf where D-genome rDNA dominance was maintained. There was upregulation of minor rDNA variants in some tissues.
Trvalý link: http://hdl.handle.net/11104/0248357