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Abstract Detail



A Colloquium Honoring Leslie D. Gottlieb

Soltis, Pamela [1], Soltis, Douglas [2].

Additivity in Polyploid Genomes: Tragopogon Allotetraploids as a Case Study.

Nearly four decades ago, genetic and biochemical additivity in polyploid genomes was demonstrated in recent allotetraploids of Tragopogon (Asteraceae). Using allozyme data, Roose and Gottlieb (1976) showed that T. mirus and T. miscellus (both 2n = 24) combined the allozyme profiles of their diploid (2n = 12) parents (T. dubius and T. porrifolius, and T. dubius and T. pratensis, respectively). This classic paper addressed the link between genotype and biochemical phenotype and provided a mechanism – enzyme multiplicity – that might explain the expanded ranges of polyploids relative to their diploid progenitors. This documented additivity is at the core of the allopolyploid paradigm, in which genes from the parental species are represented and then expressed in the new polyploid. But what if this additivity is not retained in polyploids? Recent studies of T. mirus and T. miscellus have revealed loss of genetic material at several loci, rendering these allotetraploids essentially diploid at these loci. More dramatic, chromosomes of one parental species can substitute for those of the other in the genomes of the allotetraploids, such that a tetraploid individual may have three or four copies of one parental chromosome and one or zero chromosomes of the other. These recent data demonstrate the dynamic nature of polyploid genomes and suggest that the paradigm of consistent additivity at all loci should be revised; in fact, certain loci may be retained in duplicate while others undergo loss of one parental copy. The foundational studies by Gottlieb and collaborators on enzyme additivity and conservation of isozyme number in plants provide the baseline expectations against which observations of molecular and chromosomal additivity, or not, can be evaluated.

Broader Impacts:


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1 - University of Florida, Florida Museum of Natural History, PO BOX 117800, Gainesville, FL, 32611-7800, USA
2 - University of Florida, Biology and Florida Museum of Natural History, Gainesville, FL, 32605, USA

Keywords:
Polyploidy
Tragopogon
genetic additivity.

Presentation Type: Symposium or Colloquium Presentation
Session: C1
Location: Grand Ballroom A/Riverside Hilton
Date: Monday, July 29th, 2013
Time: 11:00 AM
Number: C1010
Abstract ID:846
Candidate for Awards:None


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