Abstract Detail



Comparative Genomics/Transcriptomics

Barker, Michael [1], Jorgensen, Stacy [2], Qi, Xinshuai [3].

Ancient polyploidy is associated with higher genetic diversity in vascular plants.

Polyploidy is considered to be a major contributor to plant diversity. Nearly 30% of plant species are estimated to be recent polyploids, and almost all vascular plants have a polyploid ancestry. Polyploidy also influences other dimensions of diversity. Changes in genome organization following whole genome duplications (WGDs) may increase genetic variation in polyploid relative to diploid species. Ancient WGDs may have a significant impact on genetic diversity that lasts for millions of years. To test for evidence of higher genetic diversity in plants following ancient polyploidy, we analyzed data from a large collection of plant genomes and transcriptomes. Across 48 diploid species of vascular plants, we found a significant negative correlation between the age of their most recent ancient WGD and the expected heterozygosity of each species. The time since an ancient WGD explained approximately 25% of the difference in genetic diversity among species. To further explore this correlation, we evaluated patterns of genetic diversity in Brassica rapa, a paleohexaploid species. Consistent with our broader correlation, we found that genes derived from ancient WGDs contained significantly more genetic diversity than the non-WGD derived genes. Given the distribution of polyploidy throughout the history of vascular plants, our results suggest that ancient WGDs may significantly contribute to their genetic diversity and adaptation even after millions of years.


1 - University of Arizona, Department Of Ecology & Evolutionary Biology, P.O. Box 210088, Tucson, Arizona, 85721, US
2 - University Of Arizona, Ecology & Evolutionary Biology, 1041 E Lowell St, PO Box 210088, Tucson, AZ, 85721, United States
3 - University of Arizona, Department of Ecology & Evolutionary Biology, 1041 E. Lowell St., Tucson, AZ, 85721, USA

Keywords:
Polyploidy
Genetic diversity
WGD
paleopolyploidy.

Presentation Type: Oral Paper
Session: 25, Comparative Genomics and Transcriptomics II
Location: 102/Mayo Civic Center
Date: Tuesday, July 24th, 2018
Time: 1:45 PM
Number: 25004
Abstract ID:886
Candidate for Awards:None


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