- THIS ARTICLE
- Full Text
- Full Text (PDF)
- Data Supplement
-
All Versions of this Article:
genetics.107.072751v1
176/4/2509 most recent - Alert me when this article is cited
- Alert me if a correction is posted
- SERVICES
- Email this article to a friend
- Similar articles in this journal
- Similar articles in PubMed
- Alert me to new issues of the journal
- Download to citation manager
- Reprints & Permissions
- CITING ARTICLES
- Citing Articles via HighWire
- Citing Articles via Google Scholar
- GOOGLE SCHOLAR
- Articles by Matyásek, R.
- Articles by Kovarík, A.
- Search for Related Content
- PUBMED
- PubMed Citation
- Articles by Matyásek, R.
- Articles by Kovarík, A.
Originally published as Genetics Published Articles Ahead of Print on July 1, 2007.
Genetics, Vol. 176, 2509-2519, August 2007, Copyright © 2007
doi:10.1534/genetics.107.072751
Concerted Evolution of rDNA in Recently Formed Tragopogon Allotetraploids Is Typically Associated With an Inverse Correlation Between Gene Copy Number and Expression
Roman Matyá
ek*,
Jennifer A. Tate
,
Yoong K. Lim
,
Hana 
ruba
ová*,
Jin Koh,
Andrew R. Leitch,
Douglas E. Soltis,
Pamela S. Soltis
and
Ale Kovaík*,1
* Institute of Biophysics, Academy of Sciences of the Czech Republic, v.v.i, Laboratory of Molecular Epigenetics, Královopolská 135, CZ-61265 Brno, Czech Republic, Department of Botany, University of Florida, Gainesville, Florida 32611, School of Biological Sciences, Queen Mary, University of London, E1 4NS, UK and Florida Museum of Natural History, University of Florida, Gainesville, Florida 32611
1 Corresponding author: Institute of Biophysics, Academy of Sciences of the Czech Republic, v.v.i., Laboratory of Molecular Epigenetics, Královopolská 135, CZ-612 65 Brno, Czech Republic.
E-mail: kovarik{at}ibp.cz
We analyzed nuclear ribosomal DNA (rDNA) transcription and chromatin condensation in individuals from several populations of Tragopogon mirus and T. miscellus, allotetraploids that have formed repeatedly within only the last 80 years from T. dubius and T. porrifolius and T. dubius and T. pratensis, respectively. We identified populations with no (2), partial (2), and complete (4) nucleolar dominance. It is probable that epigenetic regulation following allopolyploidization varies between populations, with a tendency toward nucleolar dominance by one parental homeologue. Dominant rDNA loci are largely decondensed at interphase while silent loci formed condensed heterochromatic regions excluded from nucleoli. Those populations where nucleolar dominance is fixed are epigenetically more stable than those with partial or incomplete dominance. Previous studies indicated that concerted evolution has partially homogenized thousands of parental rDNA units typically reducing the copy numbers of those derived from the T. dubius diploid parent. Paradoxically, despite their low copy number, repeats of T. dubius origin dominate rDNA transcription in most populations studied, i.e., rDNA units that are genetic losers (copy numbers) are epigenetic winners (high expression).
This article has been cited by other articles:
 |
|
 |
|
  J. A. Tate, V. V. Symonds, A. N. Doust, R. J. A. Buggs, E. Mavrodiev, L. C. Majure, P. S. Soltis, and D. E. Soltis Synthetic polyploids of Tragopogon miscellus and T. mirus (Asteraceae): 60 Years after Ownbey's discovery Am. J. Botany, May 1, 2009; 96(5): 979 - 988. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. J Hegarty, G. L Barker, A. C Brennan, K. J Edwards, R. J Abbott, and S. J Hiscock Changes to gene expression associated with hybrid speciation in plants: further insights from transcriptomic studies in Senecio Phil Trans R Soc B, September 27, 2008; 363(1506): 3055 - 3069. [Abstract] [Full Text] [PDF]
|
|