Abstract Detail

Charles Heiser Special Contributed Paper Session

Soltis, Douglas [1], Buggs, Richard [2], Chamala, Srikar [3], Chester, Michael [3], Symonds, V. Vaughan [4], Tate, Jennifer [4], Mavrodiev, Evgeny [3], Schnable, Patrick [5], Barbazuk, W. Brad [3], Soltis, Pamela [1].

Tragopogon - A model for recent and recurring allopolyploidy.

Elucidating the causes and consequences of polyploidy (genome doubling) is central to understanding the origin and diversification of most eukaryotic lineages. However, much of what we know about these processes is derived from the study of crops and synthetic polyploids. Tragopogon provides a unique opportunity to investigate the genetic and genomic changes that occur in natural populations across a range of ages. This single genus contains diploids, natural allopolyploids (T.mirus, T. miscellus) that have formed repeatedly and are only 60-80 years old, synthetic F₁s,synthetic allopolyploids, as well as older Eurasian polyploids (0.5 to several mya).To date we have focused on the consequences of polyploidy in recent natural allopolyploids. Using genomic approaches, we have shown that repeated patterns of homeolog loss exceed changes in gene expression. No changes are fixed inpopulations - we have caught these gene loss and expression changes in the act. We have found extensive chromosomal variation (translocations; reciprocal monosomy/trisomy; reciprocalnullisomy/tetrasomy) in natural populations. Analyses of synthetic polyploids (S₁- S₃ generations) indicate that these changes do not appear immediately but accumulate gradually post-polyploidization. We have developed extensive genomic resources including deep transcriptome sequence data, 6X draft genome sequence for a parental diploid (T. dubius) shared by T. mirus and T. miscellus, and are developing linkage and physical maps. We have documented the parentage of an older (0.8-2.8 mya) allotetraploid (T. castellanus = T. crocifolius X T. lamottei) and now propose to develop this system for comparison with the recently formed natural allopolyploids.

Broader Impacts:

1 - University of Florida, Florida Museum of Natural History, Gainesville, FL, 32611, USA
2 - Queen Mary University of London, Biology, Mile End Road, London, E1 4NS, UK
3 - University of Florida, Biology, Gainesville, FL, 32611, USA
4 - Massey University, Institute of Molecular Biosciences, Palmerston North, New Zealand
5 - Iowa State University, Center for Plant Genomics, Ames, IA, 50011, USA

Keywords:
none specified

Presentation Type: Oral Paper:Papers for Topics
Session: 03
Location: Lindell D/Chase Park Plaza
Date: Monday, July 11th, 2011
Time: 10:00 AM
Number: 03009
Abstract ID:208