On the road to diploidization? Homoeolog loss in independently formed populations of the allopolyploid Tragopogon miscellus (Asteraceae)
Loading...
Date
2009
DOI
Open Access Location
Journal Title
Journal ISSN
Volume Title
Publisher
BioMed Central
Rights
2009 Tate et al; licensee BioMed Central Ltd.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0),
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Background: Polyploidy (whole-genome duplication) is an important speciation mechanism,particularly in plants. Gene loss, silencing, and the formation of novel gene complexes are some ofthe consequences that the new polyploid genome may experience. Despite the recurrent natureof polyploidy, little is known about the genomic outcome of independent polyploidization events.Here, we analyze the fate of genes duplicated by polyploidy (homoeologs) in multiple individualsfrom ten natural populations of Tragopogon miscellus (Asteraceae), all of which formedindependently from T. dubius and T. pratensis less than 80 years ago.Results: Of the 13 loci analyzed in 84 T. miscellus individuals, 11 showed loss of at least one parentalhomoeolog in the young allopolyploids. Two loci were retained in duplicate for all polyploidindividuals included in this study. Nearly half (48%) of the individuals examined lost a homoeologof at least one locus, with several individuals showing loss at more than one locus. Patterns of losswere stochastic among individuals from the independently formed populations, except that the T.dubius copy was lost twice as often as T. pratensis.Conclusion: This study represents the most extensive survey of the fate of genes duplicated byallopolyploidy in individuals from natural populations. Our results indicate that the road to genomedownsizing and ultimate genetic diploidization may occur quickly through homoeolog loss, but withsome genes consistently maintained as duplicates. Other genes consistently show evidence ofhomoeolog loss, suggesting repetitive aspects to polyploid genome evolution.
Description
Keywords
Polyploidy, Whole-genome duplication, Tragopogon miscellus
Citation
Tate, J. A., Joshi, P., Soltis, K. A., Soltis, P. S., & Soltis, D. E. (2009). On the road to diploidization? Homoeolog loss in independently formed populations of the allopolyploid Tragopogon miscellus (Asteraceae). Bmc Plant Biology, 9(80). doi: 10.1186/1471-2229-9-80